PlanetSide 2 Twitter feed announces a double XP weekend for PlanetSide 2, Sony Online Entertainment's recently launched MMOFPS: "To thank you for sticking with us through the growing pains, we're having a DOUBLE XP weekend (now until 9AM PST on Monday)! Don't miss out!"
Alternately, Steam is showing it's backup tool is available for the game, 9.8gb. Not sure how that plays with the launcher but Bludd's directions make it seem viable.