This is not something exclusive to the U.S. It's being done all over the world, and several countries in Europe have already gone all-digital.
As for the television spectrum, channels 52-69 are being reallocated once analog TV shuts down next February. Some of it is being auctioned off (possibly for next generation wireless internet technology and other uses). Some of it will be allocated for emergency responder use. The money that will be brought in from auctioning off the commercial part of this spectrum will go toward those $40 converter box coupons being sent out to whoever needs them (I got two). Some of it I imagine will pay down the national debt. Who knows? All I know is that this part of the spectrum could be put to more effective use.
As for auctioning off the television spectrum, it was done once before. Back in the late 70s/early 80s, channels 70-83 were taken away and became the basis of our current cell phone spectrum. Needless to say, that was put to more effective use.
Here's a couple recent threads about the DTV conversion:
http://www.democraticunderground.com/discuss/duboard.php?az=show_topic&forum=389&topic_id=3442610http://www.democraticunderground.com/discuss/duboard.php?az=show_topic&forum=389&topic_id=3392950