I would give it 10 years, since the NHL is going to be a shell of itself when this lockout ends. The bigger battle for soccer, IMHO, is that they have to win the hearts and minds of the sports pundits, who do think the sport is a minor one right now.
Weeeeeeeeeeeeeell, it's not that great once you look past the big Division I-A conferences. I'll put it to you this way: SMU football and North Texas football aren't exactly making their athletic departments rich beyond belief.