It's officially "Free Day" here at Co-Optimus, it seems. Hot on the heels of the announcement of Castle Crashers and Diablo 3 tunes being available free comes similar news for Rock Band 2 fans. A robust twenty songs will be offered as DLC to say "thank you" to those who have purchased Rock Band 2. The cost will be quite reasonable: $0, which, when converted to MS points, is around -20 or so. No word yet on when the pack is coming, nor what tunes will be in the pack. However, I'm going to go out on a limb here and predict a couple things. First, the thank you DLC will be made available the week Guitar Hero: World Tour is released. Second, there will be at least one song in this pack that's also in GH:WT. (Psst: Harmonix, if you're listening, "Hotel California.") Then again, maybe it's not just a brilliant piece of counter-marketing.