Verizon has announced that its variant of the Galaxy S3 will get the global roaming capability (so that it can be used with 2G/3G networks overseas) via a software update later this summer. The radios inside the phone already support global roaming, but Verizon has chosen not to make the ability available at launch. This is similar to what Verizon did with the Motorola RAZR, RAZR MAXX, DROID 4 and the HTC Rezound.
Verizon did fail to mention when this update will actually be offered after the launch of the phone, so it’s anyone’s guess how long their customers will have to wait. Let’s hope Verizon changes its mind sometime in the future and enables global roaming on devices right at launch, not “after a few months which might take an eternity”.