@Ragman,
It's something of a Catch-22. Until US soccer becomes a lot more popular, elite young American athletes are going to continue to be inclined towards football, baseball, basketball etc, and this, in turn, restrains the sport from being big enough to attract them.
A solo sport like tennis that operates internationally would only need one gifted American athlete beating the best of the world on a regular basis to raise it's profile here to the level that it would attract young kids, but soccer needs a whole team of very good athletes with a handful of the very best, to achieve such a goal.
It's possible of course, and particularly if teamwork rather than brilliant individual play is the foundation of the team's success as it builds momentum, but it's going to be tough. The popularity of the World Cup keeps growing in America and it was pretty substantial this time. I have to wonder though how many of the people who have been tuning in to watch the US team play, will take izzy's advice and pick a new favorite from the teams remaining and watch out the rest of the Cup? I'm sure a lot will, but certainly no where near 100%.
Until the US wins once, there's not much of a chance for the sport to make it truly big here, and the World Cup only comes around every four years.
In the meantime, none of the billions of fans worldwide are going to lose sleep waiting for us to join the party.