I think we are getting closer 
I agree with what you say, but that only happens because the Wii was able to find a new audience and therefore had the best start of the three consoles. To get those gamers, Nintendo needs the third parties as you say, and they are only coming because Nintendo is outselling the concurrence.
But if it were up to those gamers, they would prefer that those games come out for either the PS3 or the X360, and some of them are also buying these systems anyway. (The 10 million hardcores you mentioned) Others will buy no console at all, and a third group will buy a Wii, but they won't be totally happy with it.
Anyways, they are not so important anymore because the purists together with the new casual gamers will become more important this gen.







