You may not see any decent QBs among your free agents, but if not that means that there are other good players, probably WRs. If people have Shane Matthews and Drew Brees all ready, they can't also be holding onto guys like Deion Branch. SOMEBODY has to be out there ... there aren't enough roster spots in most leagues to hold all of the good players and the potential sleepers.
Quincy's receivers will benefit greatly from his performances some weeks, but he is probably going to get intercepted and sacked alot. I say dump him and pick up at the best possible free agent at ANY position, then put together a trade for a better QB. There HAS to be some good players out there, and even if you're in a league like nfl.com where you select by waiver rankings, you should still be able to get some player who has nice fantasy points and potential. In one of my leagues I grabbed Fiedler out of the free agent pool even though I all ready had Vick and Brady. You may find Quincy Morgan in your free agent pool. Whatever, just get someone who put up big numbers this week (doesn't matter if you think they will continue to, cause you're going to keep them) and offer trades.
Some advice here: Multi-player trades are more difficult to analyze and often more tempting. I don't believe in trying to rip anybody off, though. In fact, when I trade, I usually offer some pretty sweet deals. People doing well in your league will be much more difficult to trade with then people who are doing poorly, and you can upgrade a poor team without even making them a threat to you.
If you drafted well, and snagged the right free agents, you should have extra depth on your bench which can be used as tradebait. A guy like Deion Branch is a free agent in most leagues but he out-performed alot of #1 WRs this week. If you are all ready deep at WR, snag Branch and trade him to someone who has depth at Qb but who is hurting at WR. The players change from league to league but the principle is the same. Snag some high performance free agents and trade them for position upgrades.
Keep in mind that some positions are more tradeable than others. It's easier to trade a good RB than just about anyone else, whereas kickers and TEs may be very difficult to trade. In leagues that do or may start 3 WRs, Deion Branch alone may be worth a solid #2 QB, but as I said earlier, try to offer multi-player deals. Brady is STILL being called a #2 fantasy QB <boggle> so maybe someone in your league would trade you Brady in order to fill some holes.