They should drop backwards compatibility on consoles (but not handhelds) because it will cost them time and money that could be better spent elsewhere.
IBM recently sold their chip manufacturing facilities to GlobalFoundries and that includes the plant in East Fishkill, NY where the Wii U CPU is made.
- https://www-03.ibm.com/press/us/en/pressrelease/34683.wss
- http://www.extremetech.com/computing/192430-ibm-dumps-chip-unit-pays-globalfoundries-1-5-billion-to-take-the-business-off-its-hands
Right now there is no interuption in production and contracts are there until the life of the Wii U, but if they wanted the Wii U CPU in the next console they would have to renegotiate with GloFo for the manufacturing and IBM for licensing the CPU tech.
Backwards Compatibility through Software emulation also wouldn't be perfect either, as seen with the X360. MS had to make a emulation profile for each game and games weren't guaranteed to run perfectly.
In the end I think they should just sell remasters or port the games to eShop for their next console. But I do think the Wii U gamepad should be compatible with the next Nintendo console.
