The VHF frequencies for channels 2-7 (not sure about 7, somewhere around there) will be given back to the govt, which they will sell or use themselves. Mostly they are planned to be sold for broadband use. Telephone wires may become a thing of the past in the next decade, for instance.

This may also apply to UHF frequencies above a certain point, channel 50 or something. Not sure, but those won't be available to TV stations anymore, so something is happening with them.