One beneficiary will be first responders, who will receive some of the spectrum freed up. (9/11 resulted in a greater portion of the spectrum to be assigned to public safety communications.) Another portion has been auctioned to companies involved in wireless data transfer. I forget the exact figure, but I think to the tune of 12 billion bucks already.
Look, this has been in the works since the Telecommunications Act of 1995, and the original planned cut-off was in 2006. So it's been extended once before, partly because inexpensive converter boxes weren't on the market for folks with analog sets getting TV over-the air (OTA). The other reason is many broadcasters weren't ready.
Notice the delay is voluntary, and many analog stations are already gone, the broadcasters having switched to digital. For many stations that have filed plans with the FCC and scheduled necessary work, delay will have serious consequences. The old lower VHF transmitters need to come down and the UHF transmitters optimized for their new assigned channels.
One benefit is that a given frequency can carry several sub-channels, or depending on bandwidth, an HDTV channel. Digital is all or nothing, you get an adequate signal or you don't, no snowy picture. People in fringe areas are going to be affected negatively, many will need a taller antenna or will have to go to satellite. For more info, such as a list of stations in your area, what antenna type you'll need, direction of each station in degrees, etc., go to:
http://www.anteannaweb.org
Nevertheless, only a moron would schedule this thing for the dead of Winter. Tower work is dangerous enough. I bet Congress was thinking: after the election, and after the Super Bowl. Which puts it in Sweeps period of course. [smacks head]