A user at gtaforums posted this info. Right now we're in the process of clarifying whether it's valid or not but it certainly sounds interesting.
I got my Xbox Offical Magazine earlier this week and i tried to register on here, but it took me forever, anyway. A few new tidbits of information i don't think has been said.
- You can jump from rooftop to rooftop
- You can now open your car trunks, by pushing rb
Hope this is new