I'm not too worried about the level design. Recently we got Donkey Kong's level, which is possibly one of the most different levels in a Smash Bros game evar. Next to Icicle Mountain, but they're basically the same. In any case it's definitely not basic. Also, this stage seems a little less basic than some of the other battlefield stages, as the floors can crumble. While this is 3-4 platforms that crumble, the Bridge of Eldin is like 1 straight road that crumbles in the middle.
Considering the amount of stages revealed compared with the amount of characters revealed, I'd say that we don't need to worry about lack of stages, or originality. I mean, I don't see what would cause them to not be creative in this, everything else in the game is more creative than any other SSB game put together.
To be honest I'm far more worried about Zero Suit Samus' playability than the stages ^^;