I think that releasing WiiFit U this early in the lifecycle isn´t a great idea due to costs (300$+100$). The same reason I was really surprised Nintendo launched the 250$ with Nintendogs+Cats, if Nintendogs+Cats released this Christmas it would have been a huge success in my opinion.
Regarding WiiSports. I agree with the OP, it propably would be another millionseller WiiSports Resorts is proof of it in my opinion. The WiiSports for WiiU won´t release until holidays 2014 anyway by then WiiU might already have a good software library and userbase to support it.
A WiiSportsU console bundle with a decent marketing campaign is very likely.







