The first question is whether or not the Nintendo faithful will buy third-party multi-platform games. This is an important factor because most of the people who own a Wii U at the moment are the Nintendo core, people who primarily play first-party titles. It's also where the Catch-22 comes into play. For Nintendo to attract multi-platform gamers, they need multi-platform games; to attract multi-platform games, they need a base who will buy those games.
That's why Bayonetta 2 and The Wonderful 101 are important, and why Nintendo needs to spend even more money in a similar fashion. The entire industry will be watching how those games sell. Honestly, they might not sell all that well to begin with, but every single game helps. If Nintendo builds a catalog of quality exclusives, people will buy the Wii U--if some of those games are 'non-traditional' titles that manage to shift a decent amount of units, then it's quite possible that more third-party publishers will test the multi-platform waters.
Nintendo's first goal right now should just be adding games to the system. Anything they can get a commitment on. The second goal should be adding diversity to their selection. That's really what it's all about. A few angry Nintendo fanboys like to imagine that non-Nintendo gamers only care about blood, violence, and sexuality, but that's just sophistry and bitter rationalization. The real key to attracting and building a customer base that buys diverse titles is to, believe it or not, offer diverse titles. There are a LOT of gamers who want to play Mario, but they ALSO want all the other stuff.
The ball is really and truly in Nintendo's court. If they deliver, then it will be up to Nintendo gamers. Both have to come through before third-party publishers will have confidence in the Wii U. The generation is just starting. There is plenty of time to turn things around.
