This year things are changing a bit in the Stampin' Up! catalog department. Instead of a new catalog coming out on July 1st it will be released on June 1st. As such the retiring stamps list is out now. You can download a PDF copy here: Download RetiredStamps_0412_en-US.
Additionally, Stampin' Up! has announced that they will no longer carry the Decor Elements (wall art) and Simply Adorned (jewelry) lines so if you want items from these lines be sure to order them soon!