I had to exchange my 2.5 month old Mac today. I had Apple Care on it. The topic never came up in the store... what happens? Does it transfer? Did I need to "return" apple care and re-buy?
whenever they exchanged the iMacs they had to record the serial number of the new iMac so it most likely transferred over. You could always check the status by entering your new serial # here https://selfsolve.apple.com/agreementWarrantyDynamic.do