I went into Mass Effect 3's multiplayer with complete apathy, but you know what? It's pretty darn enjoyable for what it is. If you've already promoted a character and have yet to grow tired of this stuff, BioWare will have more content next week. And you don't even have to pay for it.
The "Resurgence Pack" -- coming to Xbox Live, Origin, and PlayStation Network in North America on April 10 (European PSN gets it a day later) -- adds the Firebase Hydra and Firebase Condor maps, new consumable items, additional weapons, and a character for each class.
Those characters are the Asari Justicar Adept, Krogan Battlemaster Vanguard, Batarian Soldier, Batarian Sentinel, Geth Engineer, and Geth Infiltrator. It is nice to see an expanded roster of maps, but it's frustrating how much of the ME3 multiplayer is gated behind booster packs.