I don't have a link to this. Below is from a message to dealers from GM:
All Camaro ZL1 models produced to date are currently being held by General Motors for a quality assessment. At this moment, the duration of the hold is undetermined, and may last a few more weeks. As soon as the hold is cleared, a note will be sent to all dealers to advise that 2012 Camaro ZL1 shipments are underway.
Because of the hold, the upcoming Dealer Order Submission Process (DOSP) cycle that was to be dedicated to ZL1 is being postponed. This DOSP cycle was scheduled to start this Thursday, March 1, 2012, and continues through Tuesday, March 6, 2012. A new date for this DOSP cycle will be provided in the near future.