An old idea becomes law.
Although most folks have just begun hearing about the digital transition, Congress has been debating the issue for over a decade.

February 17, 2009 deadline set.
In 2006, by a two-vote margin, the U.S. House of Representatives passed legislation to set the deadline of February 17, 2009, the date when all broadcasters must cease transmitting analog broadcast signals and start transmitting only digital broadcast signals. Once TV stations switch to digital transmission, they will return to the government valuable radio spectrum they currently use to transmit their analog channels.

Better TV, emergency response, and the Federal budget.
Congress mandated the conversion to DTV for three important reasons. First, DTV will provide higher quality picture and sound and more programming options for consumers through multiple broadcast streams. Second, ceasing analog broadcasting will free up a wide range of frequencies so they can be used for public safety such as police, fire, and emergency rescue communications. Breakdowns in emergency communication slowed the response to the September 11 terrorist attacks and Hurricane Katrina. New spectrum should help. Third, the rest of the spectrum will be auctioned off to the highest bidders — probably tech companies. The sale of this scarce asset is expected to bring in about $10 billion, maybe more. That will help reduce the federal budget deficit. It will also lead the way to new wireless services in the future