In a post on the Rock Band Forums, Harmonix Developer hmxsean reaveals that there will be Rock Band DLC next week over the holiday. No announcement what the tracks will be yet, but we do know one thing: PS3 owners will have to wait.
There will be DLC next week. An announcement will go out today or Monday.
Sony's offices are closed next week and the DLC will be postponed for a week until they come back (but they'll be back on schedule the following week when they get a double-dose of DLC awesomeness). It will go up in the Xbox Marketplace as regularly scheduled.
Nothing like waking up the day after Christmas to find yet another gift under your tree, especially one that will keep you rockin' through the new year. If you have the 360 version that is....