You said the gamecube was never really popular, and i agree with you. And yet, after 6 years and now a new console, nintendo still manage to bring a second zelda game to the 'cube. Sure, few people will buy it as the wii version will be better, but surely this gives up hope of a second wii title.
Im sure it will. I think the only way it won't is if microsoft do something really special with their next console. With the 360 being out so early i wouldn't be surprised if their next console is to. If they realise their problems and try to remake something like the wii with slightly better graphics and other games, then we may be in for a problem.
But, even if microsoft comes up with the same imagination as nintendo (which i find very unlikely) it won't be for many years yet.