There was a mistake on the PS3 RBN songs in this week's announcement. The songs originally announced are scheduled for 12/20 (America) and 12/21 (Europe).
The announcement above has been updated to reflect the correct set of songs coming out on 12/13 (America) and 12/14 (Europe). The Blog post will be updated shortly.
Mea culpa; awfully sorry for the confusion. I hope you're excited about these songs too.