As ludicrous and baseless as the Wii U's supposed system sellers have been, lets be serious here, Nintendo would have to fuck up MK8's marketing horrendously to still get out-eco'd by the Vita.
I'm going with the Wii U.
Bet with Einsam_Delphin: http://gamrconnect.vgchartz.com/thread.php?id=172355&page=11