If I were to take a few stabs in the dark:
1) Smash Bros will have DLC, as stated by Adrock. Specifically, they'll have purchasable characters, but not levels. People will cry foul about how Nintendo withheld characters just to use for DLC.
2) Mario will be given a break from platforming games, and the only Mario centric announcement in 2014 will be a new Super Mario Strikers for Wii U & 3DS, & Possibly Mario Party U.
3) Because of the gap less Mario will have, 2014 will be the year of alternate franchise announcements for Wii U & 3DS. By E3, expect an official Metroid & Zelda U announcement. Additional dark-horse candidates for a new game would be Pikmin 3DS, Fire Emblem U, or Starfox. These games when released will be critically successfull, but will be middling in retail sales.
4) Nintendo will have better sales in 2014, but only enough to make the Wii U a minor failure instead of a catastrophic one.
5) Nintendo will launch Gamecube virtual console for Wii U, with first titles being Eternal Darkness, Luigi's Mansion, & F-Zero GX. Sorry, F-Zero fans, that's the only F-Zero title that'll be released for this console generation, unless:
6) Nintendo releases an e-shop exclusive F-Zero game for 3DS. It'll be a bare-bones version of the game, with a similar feature set to the SNES original, including online multiplayer. This'll be Nintendo's biggest foray into F2P yet, requiring additional purchases for new tracks & racers.