If you pick up the Mass Effect 3 "Resurgence Pack" – it's free! – you'll be able to take part in a multiplayer event this weekend. Of course it's called "Operation Resurgence!"

Operation Resurgence surges from April 13 at 5PM PST through Monday, April 16 at 5AM PST, on Xbox 360 and PC. All participating players (basically everyone with the DLC) will get 10 percent extra experience when playing on the new maps, and will get a "Reserves Pack" that will unlock one of the random alien classes.