2.2.2 is unrootable at the moment.
Backup all your info, its going to install stock OS, from scratch.
Make sure you have your gmail accounts and contacts backed up on memory card.
and most certainly,
IF YOUR PHONE DOES NOT HAVE THE REBOOTING AND POWER CYCLING ISSUE, DO NOT PERFORM THIS UPDATE! since you do not need it.
LG / Metro stopped the shipment of LG Optimus for about 2 months due to having all their newer units updated to 2.2.2 to solve this issue that many customers were reporting on newer devices.
They also alleged that they had a shortage of electrical supplies from japan (which i think its BS).
The truth is, that we have the optimus back and its going to stay for a while. But 2.3 gingerbread is not around the corner for it.
LG on their support forums announced that the optimus line up will receive the 2.3 update, with no ETA.
reason being is this ->
Google releases new android version
Carrier requests manufacturer to perform testing on new android version (which is slow and extensive).
Manufacturer provides results to google
Google approves stability on platform -> green light to install carrier bloatware
Carrier testing for stability -> sends reports to google -> Green light from google to release the update to the public.
(or something like that) there is a load of shish involved on a new SW update.
SO be patient friends, i want gingerbread as much as everyone else.