Could there be a jump straight to UMTS instead of stopping at EDGE and then upgrading agian to UMTS? I was told in my question about 3G that the step up to EDGE wouldnt be beneficial so why not stay out of the market until they have the next step for other companies to beat them to the punch and try to implimate the higher data rate that UMTS provides?
EDGE provides triple data rates for relatively low cost. (It's really just a small, low-level tweak to GSM that optimizes it for data).
But UMTS is VERY, VERY expensive - it's more like a whole new network than an "upgrade". And at the moment, the data rates aren't that great (less than half the speed of Verizon's EV-DO technology which is already live).
EDGE is a no-brainer upgrade. UMTS is a relatively costly, risky proposition. If T-Mobile is thinking about skipping EDGE for UMTS, I say without hesitation that it would be a mistake.