Several iPhone Models to be Manufactured?

According to the Chinese newspaper Commercial Times, Quanta will be the second company to manufacture Apple iPhone, in addition to the first contractor Foxconn. It seems Quanta will manufacture the iPhone model dedicated to non-US markets, while Foxconn will supply units for US consumers.
Quanta-produced iPhone is reported to be externally different than the one available in the US, however it remains unclear if such differences are only restricted to esthetical changes, or if it also implies some internal modification (UMTS support for non US models?).
It could also be a way for Apple to fight against the grey market, as iPhone will only be available in USA from June, while Europe/Asia will most likely have to wait till October earliest. Apple might also offer black or white iPhone models as it did with the HD-based iPod... Any other idea?