• Shot Stick Advanced functions include changing the shot in midair, shooting floaters on command, and being able to upfake and then step through a defender.
• There will be no All Star Weekend in Association 2.0
• New post moves (shoulder fakes, up fakes, post hops, quick spins, etc). There will also be counters to each of the new post moves.
• Lead passes are harder to execute. Player AI has been beefed up in terms of covering cutters and reacting to passes.
• More physical play will keep players from driving straight to the rim all the time. Even if you get there, there's more contact so it's still hard to score.
• Less unwanted player bunching when the user does something outside of a play.
• Isomotion pro dribbling system has been expanded to have better countering of offensive moves. More contextual hesitation moves, stepbacks, crossovers, etc. based on what the user is doing at the moment.
• Statistical overlays (game points, career average, etc. usually shown during free throes, etc.) are back
  

• NBA 2K9 first trailer stars The Big Ticket
• Kevin Garnett to grace NBA 2K9's cover

Via 2K Sports forums