Nintendo Directs aren't purely release dates, thankfully.
I bet there will be at least one title that we either didn't see before (hopefully along the lines of F-Zero) or that we know about but want more of (hopefully Bayonetta 2).
Also I'm pretty sure that we will see a handful of new eShop titles for both Wii U and 3DS.
Nintendo UK states clearly that new games will be announced. So it's definitely not just for release dates, and hopefully not just niche eShop games. I'm guessing Yoshi and Kirby get some love. It's been a while since they've had games.
I'm not gonna expect a reveal (I'd get too hyper just considering it) but since they mentioned Monolith Softs project in the last ND I'm at least hoping for a mention, even if it's just "we'll have more information in a few months".
In a perfect world they'd announce all the games they have in development and show any footage or beta footage they have, as they need to get people interested in the Wii U more, but who knows? With the ND being worldwide I wouldn't be surprised to see one new reveal, and can't imagine it just being updates on games already released or releasing soon.