That remains to be seen. I'd like it if Nintendo loosened their IR-tracking patents so that someone can create a proper HTPC navigation remote though. Both the Wii and Wii U rely on unique interfaces that cannot be easily emulated by existing controls. Many Wii U games can do without the second screen, but they need to be patched so that they will still function without it. Some Wii games (like Super Paper Mario) use controls that can be mapped to a normal controller for 90% of play, but they still have 10% or so that relies on the camera or motion tracking.
Who knows? That's why I think the Wii U will still hang around in one form or another. There will probably be a Mini version that comes out as a lower-cost refresh (which hopefully won't be as castrated as the Wii Mini), but down the road? Until the Wii, Nintendo never really took backwards compatibility seriously. Before then there was the occasional remake (mostly for Zelda, iirc), but BC never caught on until the Wii - when they had a console capable of playing all prior games (either directly or through emulation) while having a online store for downloading those games without playing full price, or having a bunch of 8GB capacity disks that only held 100mb of data.
