The FCC has again narrowed our freq. choices with a ruling that bans the use of any wireless microphone (licensed or not) above 700 MHz after the DTV transition in February 2009. This directly involves parts of block 27, and all of blocks 28 and 29. Block 27 can still be used below 700MHz (switch settings 0,0 to 5,7) - an 8.8Mhz passband. Lectrosonic has offered a block change program. Check out the info from Trew.
Trew Audio: Breaking News from Lectrosonics (http://www.trewaudio.com/news/200808/)

well we had to see that coming. the new owners would never stand for us nobodies causing interference in their multi$$$ purchase. just glad there is some direction early, rather than chaos later. yes it sucks for those that bought into the 700 spectrum, but i also think it's only a matter of time before everything becomes licensed and moved elsewhere anyway. i look forward to the analogs going dark in Feb, maybe that will give us a little more room to breathe in what little space we have left. good luck to us all...