IMO, the US won't ever be able to replicate the soccer system in Great Britain, just from a size/concentration of teams standpoint. For example, the longest trips in the Championship League hover around 300-350 miles. In the US, that is probably on the lower end of the closest opponent.
US club owners having to undergo travel expenses for underperforming teams aren't going to want the risk of PRO/REL, especially when it works against them. The distance between opponents won't decrease if you drop down a league, but your expenses will remain the same and your fan support and revenues will decrease.
Professional sports money in the US goes the wrong way in a hurry, and fledgling clubs aren't going to have the support to sustain them during lean years. It takes a special effort to get any professional soccer team in the US to succeed, much less ones that can get knocked back to the B league right off the bat.
I hope I'm wrong and the USL's PRO/REL works, but unless teams unite to really establish some kind of safety net, I don't see how you convince a wide group of owners to keep investing something into something that potentially hemorrhages money. You'd need a large pot of owners with deep pockets that are willing to stick it out. You'd need to convince people with that kind of money to invest locally versus investing in an extrablished British club and fanbase like Reynolds/Mcelhenney or Brady did.
www.uslsoccer.com
