Mass Effect 3

[Monk]

http://social.bioware.com/forum/1/to.../index/9992705

Bioware announces the first ("of many") N7 challenge weekends. Are you a bad enough dude to beat Reapers on Silver? If you are you'll get special unlock packs. Beating the Reapers on Silver is good enough for a "commendation" pack, which contains random weapons that were originally only available through single-player DLC.

They've also attached a metagame - if the community (across all platforms) kills a million Brutes by Sunday(i think) then everyone who plays MP gets a "victory" pack. If you want to contribute to the score tally, make sure you turn "upload game feedback" on in the online options of the game.

Full details are at the link above.

edit:

Its time specific so don't bother trying to grind it RIGHT NOW if you're after the commendation packs. The event doesnt start for another couple of hours.