There was a rumor earlier that VZW will turn the Droid 4 and some LG phone into the first LTE devices that are world phones.
I suspect that many LTE phones have both GSM and LTE/CDMA radios, even if the official specs at the VZW and OEM websites indicate only LTE/CDMA capabilities. There are posts by someone with a Rezound who inserted a prepaid GSM sim into the device in Europe and it worked just fine (except sending text messages, I think). If you look at VZW and HTC's specs about the Rezound, they say nothing about the Rezound having a GSM radio.
I have a Razr and I know Motorola sells this model around the world with GSM radios. I can't imagine they actually manufacture physically different phones for different markets. I would think that they would give up enormous scale economies in manufacturing and distribution logistics is they didn't just make one phone for the whole world. Apple's iPhone 4s has both CDMA and GSM radios built into one device, for example.
Anyway, I'm going to be in London in a couple of weeks and, if I have the chance, I'll try out a GSM sim....
Also, I recall reading that LTE is really the next generation of GSM technology, not CDMA technology--hence VZW's LTE (4G) devices needing sim cards while CDMA (3G)-only devices do not.
I suspect/hope all LTE devices will be usable as world phones in due time. That story about VZW making the Droid 4 their first LTE world phone also quoted a VZW employee stating that all that's needed is for them on tweak, optimize, and test their network to turn on the world phone feature. I hop that's sooner rather than later! !
