It would be hard to tear Americans away from football, NASCAR, and baseball. I'm sure Basketball ranks right up there among them as well.
In many of the "soccer countries", soccer is really the only pro sport that draws much of a crowd anyway.
When Americans get really interested in Soccer we will win the world cup everytime and the rest of the world will find something else to be interested in.
Though I'm not following the WC closely, I have watched several games and I'll watch more now that it's getting near the end. In contrast, you'd have to drug me and tie me up to get me to watch NASCAR.
I remember when we hosted the WC -- Brazil's Ronaldo was amazed he could walk in the streets without drawing a crowd (I think he wasn't very happy about it).