They could probably release a tablet with the specs of the Wii-U by 2015, wich is what i expect them to do. This would also mean developers will start to use the Wii-U current tablet controller a lot more. Tablet's like the Asus T100 are already very close in power compared to the Wii-U only lacking in graphical power, and that only costs $350 with a keyboard dock.
Though since i'm not sure that the PowerPC architecture is really usable for a mobile platform, it's also possible that they release a tablet with different hardware but that would mean Wii-U is left out to dry.
In fact they could simply launch it as a redesign of the Wii-U.







