The AT&T LG Optimus G Pro has been rooted, the root method is the same as that for the AT&T LG Optimus G.The method is essentially a one click root method assuming you have the drivers installed and adb up and running. You can find the detailed instructions here.
xda member idle0095 has also made a video :-
The key features of the AT&T LG Optimus G Pro are:-
- 5.5 inch 1080 x 1920 pixel screen
- 1.7 GHz processor
- 2.0 GB RAM and 32.0 GB ROM
- 13.0 megapixel camera