I read somewhere that the voice does not use the LTE network as it is still "3G" and that only
data uses the 4G capabilities of LTE. That doesn't answer your question, though, as to whether
the Droid Charge has the ability to use LTE for voice.
*per VZW* it will after a update to be rolled out in the near future.... i think they are waiting to get any stability issue whit the 4G fixed first .. they dont want the "i am dropping calls on Verizon" talks to start... that is what AT&T is for..
As was said, it can't yet, but I'm sure that Verizon will roll out VoLTE to all 4G phones when they are done with their testing. Currently, the LG Revolution is the only phone that has done VoLTE, but I don't even know if that will launch with the functionality.
As long as you are in a 4G area, you can do simultaneous voice and data now, and I'm guessing that will still hold true after the update, as it won't be adding a SVDO modem to allow it in all situations like the Thunderbolt has.