Since Wii U failed, what should Nintendo have done to follow up the Wii's success?

[HokageTenshi]

i don't think there is anymore innovation able to do in gaming console with reasonable cost, just make a hi-end enough system with easier development kit for 3rd-party like the PS4/XB1 will do, with their huge popularity exclusive will be good enough to become another better choice of gaming console, but of course provided more 3rd-party making games for it is still the most important part they should accomplish in the first place...