I called this morning. They told me to go to the store to add the applecare+.
Anyone else with any luck adding on the phone vs going to the store?
I'm in California...I called AppleCare at about 7 AM local time this morning; gave them my serial number (I purchased my iPad 3 from Best Buy yesterday morning), and they quickly took my credit card information, and activated my AppleCare + coverage.
Very easy.