There is probably no chance of this ever happening. The idea behind GG is to be an affordable alternative to expensive/lengthy contracts. And they do this by being a SIM-only PAYG service, with the option of opting for a one-month rolling GoodyBag, with no commitment.
Selling mobile phones is not a service that will benifit GG.
It will never happen.
Quickest duplication ever? 2 minutes!