I did a little digging, and it seems you are correct. They need to do some tweaking to the LTE software, but because LTE is based on GSM they apparently will be able to make it compatible/global capable. There's some indication from this thread on Motorola's forums that the global capability is coming with ICS?
https://forums.motorola.com/posts/72961d1549?start=31&stop=45
At any rate, in the meantime you can apparently roam in foreign countries that have CDMA networks.
I'm still not sure that once this gets set up that you will be able to swap out your VZW SIM for one from a foreign carrier while traveling abroad though. It may just be a way for them to enable global roaming while charging you through the nose.