Update: Turns out this probably isn't the Optimus G Pro - it looks a heck of a lot more like what is being collectively dubbed the Optimus G 2. It seems an official Sprint page with build.prop info for the LS980 has been dug up (by our commenters), and it reveals a few tasty tidbits -namely, confirming Android 4.2[.2], and an MSM8974 chipset. That's no Snapdragon 600 - that's a Snapdragon 800. That processor isn't even out yet, so whatever phone this is, it's still a ways off. Our guess is the successor to the Optimus G.
While Bluetooth organization filings aren't always the most reliable way to identify a particular upcoming device, we're fairly confident in a filing that was made yesterday for a certain piece of LG hardware: the LS980.