All of the is shamelessly lifted from the NeoGaf forums, hence the numerous references to the site. Still, quite information heavy for those interested in the game:
"As we were exploring Westerns, one of the main themes to emerge was the idea of movement, of journeying across the land. At the same time, we asked, 'What does the West mean?' Is it outlaws and gunfights in one-horse towns, or the conflict between America and Mexico, or the coming of modernity to the great plains?
We couldn't really decide, and so for this to be the complete Western, we needed all three of those environments in there."-- Dan Houser
RELEASE DATE GENRE DEVELOPER May 18, 2010 (North America) western, open world, action
Rockstar San Diego May 21, 2010 (most of Europe) with online free-roam, co-op & competitive written by Dan Houser
five years in the making
XBOX 360 OR PS3 ?Early reports indicate both versions run great.
(North American ?) PS3 owners do get
a nice exclusive outfit...
SPECIAL EDITION / LIMITED EDITIONAlthough there is no real collector's edition with a cowboy hat or something, there is however an edition with some extras.
In North America, it's named Special Edition and includes the game's soundtrack, as well as some of the in-game pre-order bonuses.
In Europe, it's named Limited Edition, and also includes the soundtrack and all of the pre-order bonus content.

You can check out all the pre-order incentives
on the official website.
The in-game bonuses:
DEADLY ASSASSINJohn Marston’s “Deadly Assassin” outfit causes your Dead Eye meter to regenerate at twice the speed. With more Dead Eye, you have more time to place each shot with total accuracy, making you the deadliest gunslinger in any fight.
WAR HORSEThere are countless horses to be found in the massive world of Red Dead Redemption, but none is stronger, faster or tougher than the exclusive War Horse. Whether storming gang hideouts, exploring the wilderness for hidden treasure, or outrunning the law, the War Horse gives gunslingers an advantage in nearly every situation.
GOLDEN GUNSThe player who wields the exclusive Golden Guns receives more Fame for each kill. The more Fame you get, the more in-game side missions become available. So there will be more opportunities to duel, more kidnapped townsfolk to rescue and you can bribe lawmen for less.
America, early 1900's. The era of the cowboy is coming to an end.
When federal agents threaten his family, former outlaw John Marston is sent across the American frontier to help bring the rule of law.
Experience intense gun battles, dramatic train robberies, bounty hunting and duels during a time of violent change.
"It's America. The birth of modern America. What was gained and what was lost.
From our perspective, this movement from some kind of violent freedom to some kind of situation of much more overt state control; the movement from the individual to a larger collective where you have a lot less individual control over your life, or at least it feels that way. Whether you have that control or not is not clear but I think that movement from a primitive time to a time where we can see enormous parallels with our own time is what we found interesting about that period." -- Dan Houser
"I grew up in the foothills of gold-rush country in California and spent my summers camping in the mountains and deserts of the West. So these locations are very personal to me.
Visually, we wanted to push the theme of the dying of the Old West by showing the harshness of the environment: everything is sun-bleached and scorched, dirt and dust float in the air continually, grit and grime are in every corner of every room. Life back then was difficult, so we made it that even the buildings look as though they've lived a hard life. Along with layering dirt and grime everywhere, one of the things we did was keep the colour saturation of the world low.
Happy, bright colours tend to make for a light-hearted or fantasy experience, which was the polar-opposite of what I wanted to achieve. That isn't to say the game is black and white, but it does allow for the colourful moments to mean much more. For example, the sunsets in our game are the moments where we bring focus to the vastness and grandeur of the open landscape." -- Daren Bader, Creative Director[/INDENT]
The map is roughly twice the size of San Andreas and three times the size of Grand Theft Auto IV's Liberty City.
NEW AUSTIN ? based on: New Mexico, Texas
New Austin is home to scattered townships and forts - but far from tamed. Savage outlaws and wild animals still roam the open spaces, and wary travelers share the newly cut roads with as many bandits as farmers. Trains and coaches move quickly between the larger towns, but a sidearm is a necessity when traveling by horseback.
NUEVO PARAISO? based on: Mexico
Red soil, enormous mesas and scorching midday sun make passing through these lands an unforgettable journey. In quieter times, the locals are not likely to bother a stranger - but there is talk of a civil war brewing in the hills, and mounted army patrols are quick to extinguish any signs of trouble.
WEST ELIZABETH? based on: Wyoming, Colorado
Home to the bustling Blackwater, one of the many modern, burgeoning new townships that sprung up across America in the dying days of the Old West.
West Elizabeth may provide a taste of early 20th century modernity, but also its fair share of wilderness and danger. From the wolves prowling the snows of Nekoti Rock to the fierce Grizzlies in the forests above Manzanita to the ruthless card sharks at the tables in Blackwater - traveling the North requires caution and wile.

Fun facts:
You can fast travel from any campsite to any visited town.
When you're stranded in the middle of nowhere, the game will make sure there's a wild horse around for you to capture.
Methods of transportation:
HORSEObviously! There is however quite a variety of breeds, with different personalities, speeds and stamina. Wild horses can be tamed.
Horses auto-jump over obstacles, but aren't stupid and won't jump off cliffs.
In multiplayer, level 1 players start off with a mule.
STAGECOACHStagecoaches can be used as taxis and allow you to skip the ride.
TRAINSome areas have a railroad network which you can use.
Trains are similar to stagecoaches, you either enjoy the ride or you skip the travel.
RIVERBOAT Steamboats ply the San Luis River.

[INDENT]
POPULATION no NPC (non-playable character) is the same, their appearances are randomly generated
houses can be broken into, possessions can be stolen
hundreds of random events (which happen to NPCs as well)
there are still native Americans, but not living in tipis anymore
TOWNS can be turned into ghost towns, will remain like that for at least 2 in-game days
gangs can take over towns
GANGS gang hideouts can be cleared out[/INDENT]
"Rockstar has a very odd place in the industry because there's an audience who appreciates the way its games criticize our culture and there's an audience who just love running around and blowing things up. I think the first group will love to see Rockstar explore the mythology of the Old West, but it's hard to know if the second will find that as interesting."-- Tom Bissell, author
ON FOOT CONTROLS movement: left analog, X/A to sprint (tap, then hold), square/X to jump & climb
camera: right analog (press for Dead Eye)
weapons: d-pad hotkeys, L1/LB weapon wheel, circle/B to holster your weapon
shooting: R1/RB cover, L2/LT to aim, R2/RT to shoot, square/X for an evasive roll
horse: d-pad up to whistle for a horse, triangle/Y to mount
HORSEBACK CONTROLS (dis)mount: triangle/Y
movement: left analog, X/A to use spurs (increases speed), R1/RB to pull on reins (slow down)
shooting: L1/LB to draw a weapon, L2/LT to aim, R2/RT to shoot
camera: right analog (press for Dead Eye)
DIFFICULTYThe game has three difficulty settings, each with their own aiming system.
Casual (full auto-aim + faster regenerating health)
Normal (snap-to-target with precise aiming using the right stick)
Expert (free aim)
HEALTHWhen injured, your health regenerates, but you can speed it up with food or medicine.
APPEARANCEThere are many outfits to buy and earn. Ranging from your original cowboy garments to elegant suits. There is also headgear (ie hats & bandannas) and you upgrade things like bandoliers to carry more ammo.
INVENTORYMarston can carry a ton of stuff with him.
campsites (which can be set up anywhere to add new "safe houses")
newspapers
treasure maps
wanted posters
weapons & binoculars
various story-related items[/INDENT]

Choices you make will affect your levels of Honor and Fame, changing the way townsfolk respond to you and gaining you the reputation of a well-respected and law-abiding gunslinger - or a notorious outlaw.
HONORYour Honor changes based on the choices you make. Behaving honorably by rescuing stranded travelers, helping townsfolk in need or choosing to capture instead of killing criminals for bounty will increase your Honor. Honorable men earn favorable discounts with merchants, and lawmen turn a blind eye to small crimes. You are of course always free to choose a dishonorable path instead; killing townsfolk, stealing horses and robbing banks will see your Honor plummet… but it might also make you rich.
FAMEThe actions you take will also affect your Fame throughout the territories. Becoming more famous will have its rewards: people will come to you for help and greet you by name; shopkeepers will give you discounts, and new opportunities for work will open on the frontier. But a famous gunslinger attracts attention, and gunfighters will come out of the woodwork to challenge you to duels in the hope of making a name for themselves.[/INDENT]

There are over 30 weapons in the game, including:
HANDGUNS Cattleman revolver
Colt Police Positive revolver
LeMat revolver
Schofield revolver
Borchardt C-93 pistol
Colt 1903 pistol
Mauser pistol
Volcanic pistol
RIFLES Carcano rifle
Henry rifle
Krag-Jørgensen M1898
Sharps rifle
Spencer repeating rifle
Springfield Model 1873
Winchester 1894
Winchester 1903
SHOTGUNS Browning Automatic 5
Winchester Model 1897
Double-barreled shotgun
Sawed-off shotgun
OTHER Knife
Throwing knife
Lasso
Dynamite
Molotov cocktail
"Sometimes you can be the hero, sometimes you can be the bad guy, and sometimes while you're deciding what to do, a bear comes out of nowhere and eats someone."-- Dan Houser
Fun fact: None of these activities are marked on the map. Only story missions are.[/INDENT]
ANIMALSThere are over 40 animal species to hunt, ranging from beavers to grizzly bears. Use bait to attract animals.
Meat, skin, horns, claws and more can all be exchanged for money.
horses, cows, pigs, chickens
dogs, coyotes, wolves
cougars, grizzly bears
deer, bison, bighorn sheep, elk
rattlesnakes, armadillos, beavers
vultures, bats
...
TREASURESA treasure map will lead you to gold, or another map.
CRIMINALSWanted posters feature criminals which can be tracked down for a reward.
When given a "dead or alive" option, the latter nets you a larger reward. If you kill the felon, proof of death must be brought back to town.
PLANTSCertain plants and flowers can be sold to pharmacists. [/INDENT]

card games (poker, Blackjack, etc.)
knife game / 5-finger fillet
Liar's Dice
horseshoes
arm wrestling
bull riding
races
movie theatres

cattle herding
burglary
bank robbery
dueling
sharpshooting (birds)