Nintendo will be pushed out of the hardware business with this generation and will pull a Sega and become a software only company. They don't have pockets deep enough to afford even a single big hardware miss, and the Wii U will be a miss.
Even stronger companies like Sony are finding it dangerous to stay in the gaming hardware business. If the PS4 doesn't sell well enough, it's questionable whether there will be a PS5 given the horrible condition Sony is in (for reference, their stock is roughly, inflation adjusted, where it was 25 to 28 years ago).
Just my opinion, but I believe Sony and Nintendo will fade in the hardware business, and Valve will replace one of them. The winners will have very large online communities, neither Sony nor Nintendo have that going for them, whereas Valve and Microsoft do.