Nah, not the first. BoE (walk-off+stage effects), Delfino Plaza (maybe), possibly Lylat Cruise (if low-grav in places, plus possible stage effects), the outside castle (maybe, if fireballs and such chip away or strike the stage), the Halberd (probably), the Mario Kart stage (almost assuredly)...most of them so far, in fact.
Know what I just realized? When watching the second trailer, you can see near the end, on Pit's stage, that everything can be broken: the floor and the platforms. I think that the clouds also begin to fade away after a while of being stood upon (like Yoshi's N64 stage). Maybe there's more stuff below (like if all the clouds vanish, everyone falls to another level). That would be neat! It would also result in banned-ness.