bbman: Roaming isnt going to be an issue as quad band wCDMA phones are already being released.
Quad UMTS doesn't solve the roaming issue. The only Quad band UMTS phones are either 850+1700+1900+2100 or 900+1700+1900+2100, nobody (that I'm aware of) has yet commercially released a handset that does UMTS 850 + 900.
First we had dual band then tri band and then quad band. Now we need 5!