When I heard the Nintendo Direct mention the game would have a different, multi-player (they mentioned this, right?) feel to it, I think it'd be pretty neat if they created a game where all the past Links come back and you can switch between them with different play-styles.
Maybe not EVERY Link, but the main console Links since they're the most important to the series overall...NES Link, LTTP Link, Ocarina Link, WW Link, Twilight Link, and SS Link. Adventure Link is the NES Link, Awakening and Oracle is the LTTP Link, Majora is the Ocarina Link, Phantom Hourglass is the WW Link, so the only individual Link's left out are the minor Minish Cap and Spirit Tracks Link, which wouldn't be a major admission really. The lesser games could be referenced though, like Majora appearing and such.
So, each Link could be done in the style seen in the Wii U demo reel, but with their designs changed around to give them more of an individual appearance...LTTP Link could have reddish hair, and maybe a bit effeminate as a reference to his old pink hair, Twilight Link could be more rugged and muscular since he's a farmer, etc. And then each Link would have their own play-style, like LTTP Link would focus on magic, since that game had the most magic abilities, using the Medallions and Element Rods, while NES Link would be the master when it comes to using basic weapons, and Wind Waker Link would be very quick and nimble like he was in Wind Waker.
And then you'd either switch between them in single-player, or in co-op, to solve dungeons and fight enemies.