I would guess 2016, hopefully along with an F-Zero or Wave Race, proper 3D Mario, like Super Mario 64.
Bringing Pilot Wings back would be cool too.
I hope Nintendo can keep Zelda and Starfox as 2015 releases, as well as announcing some big surprises, like New IPs as they really could do with refreshing their line-up. I'm cool with them always having a good amount of focus on Mario games, but they often leave out other franchises that so many of their fans would love them to support nearly as much.
One thing they would be wise to do is announce a full 3D Pokemon action RPG, with Amiibo support.
If they want to boost Wii U sales then games like that are what they need to release. If they could rip-off Kingdom Hearts, with a new core character of their own creation, who goes on an adventure meeting characters from the various different Nintendo franchises, maybe make it into an MMORPG or a huge RPG that would be an enormous success.
There's so many games that Nintendo could easily do to bring people in droves to the Wii U.
I'd be cool with a side scrolling style Metroid (similar in visual style to Strider) and a first person game.
Maybe we could get the side scrolling version in late 2015 and a full Prime style setting in late 2016.
