regarding gameplay - I'm rather peeved that they put "Dark Pit" as another character. I mean, he's an exact clone of Pit, just... "dark". Why couldn't that have been an outfit change? So far that's my biggest gripe about it -- wasted a perfectly good slot on a color pallet swap.
Besides that, I'm enjoying the game -- forgot how much I like Smash since its been forever since I've played the Wii one
I hope they do something really special with the Wii-U version to make it different from the 3DS version (even though they already said they were not going to change the roster).
Now that they've already launched the 3DS version, they could totally add new secret unlockable characters in the Wii-U version and say that they were referring to the "starting roster" if people complain - I'd be alright with that