I won't be getting a Wii U. Nothing on there i would really enjoy so much to make me want to buy it. NSMB Wii U looks like NSMB Wii with higher resolution textures and new levels (which you can just download for your regular wii if you have an sd card).
Missing the next SSB will be a bit annoying, but i wouldn't have anyone to play it with anyway. My friends and i have been playing brawl lately when we hang out, but nobody has a Wii U. Also, SSB is most fun when the people you are playing are right next to you.