The following are the features known so far with San Andreas:

Main Details
"It's the third part in a loosely held together trilogy that started in 2001, that went to the mid '80s and has now come to the early '90s," said Dan Houser.
Three cities to roam beginning with "Los Santos" (Los Angeles), then going to "San Fierro" (San Francisco) and ending up at "Las Venturra" (Las Vegas). Countryside is inbetween each city. Los Santos will appear on the bottom-right side of the map.
The game's story has tripled in length as well as the number of music tracks when compared to Vice City.
Setting is the Early 1990s.
There are 12 small towns in the countryside.
There will be no online multi-player. There will, however, be a co-op mode.
60,000 pedestrian comments.
Around 200 vehicles.
Your character's name is "Carl Johnson." "Carl is the most detailed character to appear in any GTA game before" now. (From Play Magazine)
"The entire game area is approximately four to six times as large as the entirety of either of the previous entries in the series," said Dan Houser. This most likely means land area.
You will be able to swim, but it won't be a major part of the game. You can climb out of your car window if you drive into water.
Abilities to control hairstyle, physique, weight, driving skills, clothes, possessions, weapon skills, character (how you act) and relationships.
About 16,000 unique objects and buildings will be included.
Four-person drive-by shootings are possible.
A new "stamina meter" gives you an indication of how much Carl needs to eat and exercise. You can get fat.
BMX Bicycles will be present. To pedal a bike, repeatedly tap (X). To bounce your car, use the right analog stick. You can also perform wheelies.
The auto-target system has been improved in that targets are green (healthy), yellow (below average health) and red (near death).
If you get stuck in the game, the game will adjust itself to make it easier. It will not be noticably easier, though.
More diverse missions will be present.
You can now get a haircut. It won't be something just to do for fun. Some missions require it. People will treat you by the way you dress and look. Three confirmed hairstyles include "dripping Jheri curls, a fashionable Afro and a towering flattop."
Some cops now ride on motorcycles are very reminiscent of the California Highway Patrol (CHiPs). They can hold on to the back of your car to try to catch you.
You have the ability to run a casino "which you will have bought and built," said Dan Houser.
You can rob houses, but they must be well-planned or you will not succeed.
Mountains and rivers are present in the countryside, including one huge mountain. Desert is also in the game.
The huge mountain is called Mount Chiliad. It is the largest object in the game. The mountain is "about half a mile tall" and has plenty of trails, cliff-top roads and tunnels.

Will so buy it when it comes out on the Xbox........

Though by then, the Xbox 2 and PS3 might be out, so who knows.

xbox 2 and ps3 comes out on 2006 i think
and grand theft auto on xbox comes out on june
[=

i got it the first day it came out in october, stood in ebgames for over an hour. got home played all night and all day. game is awesome.