Honestly, I'd rather they completely ditch backwards compatibility if it meant it could keep their system costs lower and thus more competitive. Granted, it's hard to use the argument with Gamecube to Wii to Wii U, since each is basically just a directly improved version of the last. If Nintendo really is looking to adopt a completely different architecture with their new console though, perhaps matching Microsoft and Sony would be for the best to make third parties more likely to contribute to the platform (or at least to help alleviate any hardware based excuses).
Backwards compatibility is incredibly valuable to Nintendo though since it can help gamers fill in time during long game droughts, so unless Nintendo can do a full 180 on their third party issues next generation, they'll probably want to do their best to retain backwards compatibility in the the easiest to use way possible.
