THE FOLLOWING HAS BEEN UPDATED SINCE ORIGINALLY POSTED.
I removed the hive top feeders from both of our hives on Friday the 13th. I installed double-frame feeders instead (aka division board feeders). The whole procedure was fraught with peril, plenty of opportunity to injure or kill a queen bee. Then today I was cleaning up the hive top feeders and noticed these dead bees on the underside of one of them:
Does the bee on the end look like a dead queen to you? Just asking.
UPDATE (August 20/11): I had yet to spot a queen in any of our hives at this point. The large bee in this photo is clearly not a queen.