Cities XL looks exciting.
And if what Pescado suggests is true (a 3rd party neighborhood editor), then I'm also excited about that. Really, the one thing I miss most about TS2 is that I can't build a neighborhood up from scratch anymore. Well, technically I guess I could, but it would always just be another version of Sunset Valley. I think if they ever made an OFB pack, a neighborhood editor would fit in perfectly, but of course it's EA, so logic can be thrown out.