If I may respectfully disagree:
I do not believe that the next GTA should have create-a-character or make-a-gang. The GTA games, at least the 3d ones, are about story. You take a character through a menagerie of violent and/or impulsive criminal caricatures, and you use them or play them off on each other to get to the end. I think making your own character would chop that kind of story off at the knees. As has been evidenced by the past games, motivations are different when your gang is gangsta, mafia, or Triad. Claude was a mute, and that only succeeded to make his story happen around him rather than through him.
Secondly, there isn't really any reason to have gangs. Whenever push comes to shove, you're doing all the heavy lifting by yourself anyway. Also, babysitting an AI adds another layer of tedium to the "drive here; shoot them" mechanic.
I personally would agree that Vice City is not preferable to San Andreas. VC has beach and swamp while San Andreas has beach, woodlands, and desert. However, the natural progression was that Rockstar learned to do more with the same space, hence VC is bigger than Liberty, and San Andreas is still larger. I would rather them take the story to VC and refine the new game engine than jump straight into San Andreas. I can wait.
Finally, I think that Rockstar should opt for a bit more sidemissions. I don't think that they should go the path of Saints Row and totally inundate the game with BS, rather there should be a bit more to do than we had in GTAIV
Never attribute to malice that which can be adequately explained by stupidity.