Microsoft has expanded Xbox Live to enable new entertainment options such as YouTube and Verizon’s FiOS TV, but the bread and butter of the Xbox 360 remains games. This week will see a slew of attention-grabbing new content on Xbox Live for some of the year’s biggest titles. Battlefield 3 finally gets its Back to Karkand expansion, available for $15, or free to those who purchased the Battlefield 3 Limited Edition retail package. Gears of War 3 kicks off its 12 Days of Gearsmas celebration with the RAAM’s Shadow campaign. You can read my review here. I didn’t like it. And Assassin’s Creed Revelations receives the first of several content bundles with the Ancestors Character Pack, which adds a few new faces to the multiplayer.