As much as I like certain Nintendo games, my GameCube is currently collecting dust. They're losing marketshare like crazy and not attracting any 3rd party developers. Nintendo develops innovative games, but they can't do it all by themselves and still expect people to flock to their console.
I hope Nintendo doesn't go down like Sega did (because that will be a horrible shame) but I'll definately be getting a 'PS3' rather than sticking with Nintendo.