I bought Drawn to Life. It's told me that while a game's design may seem genius, and while critics and reporters might love the half hour they spend with the game whenever they get the chance, that deep down, a gimmick is still a gimmick, and you should wait and see if the gimmick is worth using for the hours you'd involve yourself with said game.
So, I'm waiting on Scribblenauts. The psuedo-prequel scared me away. I'll see what people who beat the game have to say, and I'll see what those who can't complete have to put in to, then pick it up later if I'm still interested.