Let me modify your statement a tad. The FCC did not mandate anyone move to UHF, that was a decision each station made on their own, and depending on the individual city and area topography, most of the stations that elected to stay on their VHF assignments are kicking themselves. We have a station that elected to stay on their VHF assignment before we bought it, so the damage was done. The #1 station by a long shot has dropped to near last place... VHF ain't the place to be with digital TV. But wait...
What the FCC REALLY wants is the UHF spectrum and there is yet another spectrum auction coming up with initial offers of spectrum in the LA area (for example) hovering around $700 MILLION dollars for a station to leave. Another option is to take lesser cash and move off UHF, and back to VHF.
Stay tuned....