Also attributable in part to the cost of building and operating a digital station alongside an analog was WYLE of Florence AL, although given their circumstances, they probably would have gone under even without the digital transition.
They did make some effort (weak as it was!) to retain their license. It seems the FCC didn't buy 24 hours of color bars as "broadcasting", and they fell afoul of the "one year off the air and you're out" law.
To be perfectly honest I think they'd stand at least a 50/50 chance of resurrecting their license on appeal. There has been a VERY hands-off attitude towards what programming a station carries, and while an ordinary viewer certainly wouldn't consider a test pattern "broadcasting" I think a good case could be made that from a legal standpoint, it is. Whether they can afford the legal fees to launch such an appeal is another question.
(and indeed, there's a fair chance they'd still go under anyway...)
A station that recently "un-deleted" themselves is WFUP-45 in Vanderbilt, Mich.. (10 miles north of Gaylord in the northern Lower Peninsula) They'd refused to file a DTV application, planning on using co-owned WFQX-DT 47 Cadillac to cover both stations' analog service areas.
The stations were then sold, and the new owners decided they wanted to keep WFUP after all. I think they'd already lost their second channel, but they now have a CP to flash-cut to digital on channel 45.
KLEP-17, a tiny station operated by an Arkansas school district, surrendered their analog license at the very beginning of the transition.