Broadcasting & Cable is reporting in a story that the FCC voted to ban mics in the 700mhz block (but the story is not real informative about existing mics.)
To the FCC, there are only a handful of licensed users in the range our (unlicensed) mics operate in.
http://www.broadcastingcable.com/article/CA6589511.html
The following is mostly conjecture on my part:
I've seen the allocation for the recently auctioned 700mhz band and part of it will be dedicated to public service where our mics will definitely be forbidden to operate, I think.
I'm guessing we'll be able to use our existing mics for a while, if we're careful, but won't be able to get any new ones in the "c" block. Our choice of clear frequencies may dwindle, though. Too bad. Even at the Super Bowl I had no trouble getting allocated a channel 'cause not many of us use block "c".