A Spanish newsletter from Nintendo of Europe appears to have inadvertently revealed the release date of Mario Kart 8 as April next year. The info was apparently quickly removed but one Twitter fan managed to take a screenshot before it went.
If true though one of the questions it raises is what, if anything, is going to be released in January through March. Nintendo has announced a few titles for 2014, but it's hard to imagine Bayonetta 2, Super Smash Bros., or Monolith Soft's X, either being ready in time or Nintendo wanting to release them at such a relatively quiet time of the year.
The likes of Super Mario 3D World, Wii Fit U, Donkey Kong Country: Tropical Freeze, Zelda: The Wind Waker HD, and Wii Party U are all supposed to be out this year, which leaves Nintendo with potentially another games drought early next year.
The currently unscheduled Yarn Yoshi could be one title being held back for early 2014, but the only other announced first party titles for the Wii U are Shin Megami Tensei X Fire Emblem and the new Zelda - and they're even less likely to be released before April.