I just found out about this.
I have an 04 AWD V8 with 94k and recently a code has came up that I may need to replace the cats. Thanks to this forum a recieved a clue that there may be free replacements by the dealership. Turns out there is. According to fleetleader.phh.com/recalls/2010/recallsOct1-222010.pdf refers to a "Special Coverage Adjustment #10127" warranty Extension. Give the dealer your VIN to see if it applies but here is the skinny. covers some 04-05 models with a 4.6L for a period of 12yrs or 200,000 mi. Repairs at no cost to customer.
I'm so happy. Good work Cadillac.