Subsequent to my posting about unlocked iPhone 4s in the US, it's now no longer a rumour. Prices are $649 and $749. 3Gs isn't being offered unlocked. I got the Verizon thing wrong though - apparently the unlock doesn't apply to Verizon, the CDMA tech carrier, nor then would it work on Sprint who use the same system.
I wonder how those customers feel about Apple's decision? Seems to lack fairness...
Lucky we don't live in the US as far as our telecoms are concerned. :-)