Saw the beta, looks like you can do some fun things with the tiles, but since its a platform game any PC level creator blows it out of the water if they work with 3DS Max, Blender, or Maya. The tiles are fun and being able to texture without knowing anything is nice as well, but the buy in price for the console will exclude a lot of people and the limitations will push serious level designers away.
From what I've heard, from those I spoke with, few people ever actually finish a level, they mostly just claim that everyone else will make cool levels for them. So I doubt we'll see anything astounding any time soon.