If they get regulated and based in the UK I would say they will be in a good spot to take US customers. The UK authorities are making it quite clear they will regard all activities as occurring in the UK and won't bar anyone from other countries from participating in their gaming activities. They will pay no heed to any other government's claim of jurisdiction over online or phone gaming, to them it is the same as if you flew on a plane and played in one of the land-based casinos when you make a bet with one of their regulated operations. With the potential size and intentions of the authorities in the UK, I highly doubt they will cave into US government wishes on this one. If they want credibility they will maintain independence from any outside influence.