iPhone 4S: One phone, multiple carriers?

[gottafly]

since the availability of unlocked units has increased dramatically, combined with the new chipset that allows units to be used on more than one carrier, my question is this:

Has anyone with an unlocked iPhone 4S been able to use one handset on more than one carrier? in other words, subscribe to CDMA carrier, but install GSM sim card and been able to "flip" between service providers by using software settings, rather than physically removing sim card?

 

[iVoid]

Apple specifically states the unlocked iPhone 4S will not work on CMDA carriers (like Verizon and Sprint).

So in the US, that leaves AT&T and T-Mobile (with edge data).

So far it seems that if you get a Sprint or Verizon iPhone 4S, they will unlock the SIM for international carriers if you're a customer in good standing for 60 days. Everything I've read so far indicates that still won't work on AT&T or T-Mobile (i.e. the sim is still locked to Sprint/Verizon in the US).