Third parties would rather XBox or PS be the system of choice for consumers, because on those platforms they don't have to compete with the world's largest gaming software maker. I don't blame them. The PS2 environment was ideal as a third party. Games like Metal Gear, Final Fantasy and GTA were the system sellers. The same is true on XBox360 where COD is the lead franchise. On a Nintendo platform you are always competing with MarioBros or MarioKart for consumer dollars and promotion.
I think 3rd party support is coming for WiiU and we'll hear about it soon. But if it's not, the best thing Nintendo could do is buy Take Two. Then they won't need to worry about it.