One thing I desperately want them to do is change the "on-foot" style from GTA4. That was the main thing that I wasn't very fond of. I ran too slowly and found myself tripping over my own shoe laces more times than I care to remember. Vice City had it right. You ran fast, but you would too if your life depended on getting out of a firefight, or a car on fire about to explode. You wouldn't trip on your own feet and seizure out on the ground for a sec, resulting in your demise. But it looks like they changed that in Red Dead Redemption, so I can safely guess they're aware the fans weren't too adoring of that and will have it changed for the next GTA as well.