Today (November 13th, 2011), while playing MW3 on Xbox I noticed I was getting Double XP for most of the day. I know that you can enable it a few different ways, but I didn't do anything special this weekend. This was player XP, so like kill confirmed was giving me 100 score for each tag.
While playing, my accounts tag (not sure if thats the right name, but where the emblem, title, and more show up) had a red/orange 'XP' icon in the top right.
I didn't do anything that I can think of to enable this. And I haven't done anything special in the game (and I didn't pay for Elite). I was a beta tester for Elite though.
I couldn't find anything online stating it was a double XP weekend either.
My question is - how are other ways to get Double XP?