The CDMA carriers have this nasty habit of refusing to activate any CDMA phone not originally sold for their network (Sprint still has to sell a massive number of iPhones due to their contract with Apple, but Verizon is really no better). So that's out.
But it's been confirmed that you can buy the Verizon iPhone to use on the AT&T network with an AT&T SIM card, but only on AT&T's GSM/HSPA/HSPA+ bands (what AT&T likes to call 4G). Unfortunately, the Verizon iPhone 5 won't work for AT&T's LTE network because the two models have different radios that support different LTE bands.
I don't think we know yet how the Verizon iPhone 5 will work overseas with a SIM card from an overseas carrier that supports LTE bands 1, 3, or 5. Is it just a matter of swapping SIM cards or will the baseband need to be changed?
In any case, if you buy the Verizon iPhone 5 on contract you are still on the hook for either the two year agreement or paying the ETF.
Has anyone been quoted a full price yet for the Verizon iPhone 5?