If this recent FCC filing is any indication, it looks like AT&T won't have US exclusivity over the LG Optimus G Pro for much longer. The document points to a LG VS980 that's clearly headed for Verizon; it supports the carrier's LTE bands and the model number is in line with other Verizon LG smartphones like the LG Intuition (VS950). Seeing as the AT&T model is marked as the E980, our Magic 8 Ball says that all signs point to the VS980 being the Big Red version of the Optimus G Pro. So that'd make at least a couple of ways Americans can get their hands on the LG smartphone, which is two more than anyone in the UK.
*Verizon has acquired AOL, Engadget's parent company. However, Engadget maintains full editorial control, and Verizon will have to pry it from our cold, dead hands.