GamesRadar.com is reporting some rather interesting new details on SanAn from an as-of-yet unknown source. Most interesting of which would be (as many have guessed from the intitial plot summary) that San Andreas will be an entire state featuring three cities. Rockstar's original press release made mention of a Los Santos, which with the screenshots and Cali's observation thereof, seems to be based on Los Angeles. GamesRadar not only echoes this, but speaks of two other cities as well- San Fierro, said to be based on San Francisco, and Las Venturra which might just be based on Las Vegas.
Also mentioned in the article are a new 'stamina meter' which comes with the need to eat in the game, as well as more interactive interior sections for the player to rob or gamble money in a casino. There's also mention of improved AI allowing the player to recruit gang members for missions and such.
We've yet to find official confirmation on any of this, but could it be that this info is from the issue of Game Informer that's floating around E3? Only time will tell. The full article can be found by following this link to GamesRadar.com.