It appears as if the Korean variant that has been out for a few days has already been rooted. The root method comes by way of a root method that was previously available for the LG G2. It is not entirely clear as to whether or not this root method will work on US variants, but there are a few proof pics and various users have verified that it is indeed working over at XDA. The method is pretty simple.
1. Install LG Driver
2. Enable USB debugging
3. Download Roottool and extract
4. Run the Run.bat
5. press any key to go to recovery
6. Choose apply update from adb in recovery
7. press any key from the command window
8. Press Reboot
9. Profit
This does not install the SuperSU app so you will need to grab that from the play store, and update the binaries. Head to the link below for the tool download.
Via XDA