I'm getting a Wii U version along with Smash and Bayonetta 2.
While it didn't work for me, a lot of people who I know have 3DSes got Smash for 3DS - and all but one is planning on getting Smash for Wii U.
It's brilliant on the part of Nintendo, especially that eight-player Smash.
I WON A BET AGAINST AZUREN! WOOOOOOOOOOAAAAAAAAHHHHHHHHHHHHHHHHHHH
:3