The only thing I don't quite like is the community levels. Some of them are amazing, don't get me wrong, and this extends the replay value infinitely. The problem for me comes from the new tools. You can now make full-on games, not just levels in a platforming game. RPG's, space shooters, first-person shooters, you name it. Since you *can* do that, everyone is doing it. It's more difficult than it should be to find platforming levels.
The first LittleBigPlanet was the first game I got a platinum trophy on. I played the hell out of it. I think I'll do the same with LBP2 now as well.