UPDATE 6 2:49pm: National Journal's Marc Ambinder tweets: FEMA official concedes "glitch"; says that it appears (maybe) to be related to how satellite and cable providers prepped their equipment.
UPDATE 7 2:59pm: Some DirectTV customers reported hearing Lady Gaga's “Paparazzi” play during the test. Some Comcast subscribers saw their cable boxes turn to QVC before the alert, while Time Warner Cable customers in New York did not see any alert at all.
UPDATE 8 4:05pm: Senate Homeland Security and Governmental Affairs Committee Chairman released this statement to Business Insider:
"The weaknesses exposed by today's test of the emergency alert system are unacceptable. Government and media carriers must work together to make sure the system does what it is intended to do, which is to transmit a nationwide message from the President in a crisis. I commend FEMA for carrying out this long-overdue, first-ever, nationwide test of the system. Without it, we would never have known the extent of the system's vulnerabilities."
http://www.businessinsider.com/attention-your-tv-is-about-to-be-taken-over-by-the-government-2011-11-1
What's ironic here is that the networks are very quick with breaking news all on their own, while this EAS system apparently doesn't work. If they hadn't tested this and there were an emergency, broadcasters couldn't have intervened to inform the public, all while a scrambled Lady Gaga plays on and on, or the TV randomly gets stuck on Home Shopping Network.