Looks exactly like the Nightlife expansion for the Sims 2 - it's the same premise but I expect it'll be executed much better. There were never enough random sims in the Sims 2 Nightlife community lots.
Actually, come to think of it, the Sims 3 does community lots much better than Sims 2 - no irritating loading screens, instead it takes about 5 seconds to load the objects and sims.
Yeah, it does look the same, but it looks like there is going to be a lot more in this expansion than Nightlife.
I am curious as to how this is going to fit onto the community lots. Mine is pretty full as it is. Though, my guess is from the skyscrapers and stuff is that it is going to a be a completely new world. You will drive to the city and then it will be like visiting a new town. I think the Sims 2 apartment life could be thrown into this.