Hmm...good question.
Accelerating factors are three fold:
1) how successful this new NBC deal is
2) how the USMNT does in Brazil
3) how NYFC changes MLS
Do you think the NBC deal will make a huge difference? There have been a few attempts to get Football going in the US. Wasn't the 94 world cup essentially there to try and big the sport up in the states? To be honest I think it would be an interesting thing to have a strong US league. Surely it would be a good thing for the sport worldwide?