There might be some of you who can't help but feel that Vegas 2 seems like an expansion pack. Aside from a few new gameplay mechanics, such as the ability to sprint, it does all still feel the same. That's not really a bad thing though as the original was great.
One key thing that will help differentiate 2 from 1 is that the game will take place all over Vegas now. Instead of just being in casinos all the time, you'll be able to explore the rest of Vegas such as night clubs, a library, the monorail, and the convention center where an E3 like event is taking place. They seemed to be influenced heavily by the TV show CSI as the show usually takes place all over Vegas.