All I know is if I were an early adopter and had tens of thousands of coins and a bunch of cash I'd be crashing a few markets right now to buy back up on the cheap.
Hell, it only takes 1000 BTC to drop Tradehill a few bucks. I'd be trolling hard.
Pretty sure about everyone in the world has thought of that. The problem is it wouldn't work. Best case scenario is the downward pressure would be reversed when you buy the coins back, and you'll end up right back where you started minus transaction fees. Even more likely though is you will sell a lot of coins cheap, making it attractive for new buyers to come in and so when you go to buy all the coins back it will have to be for a higher price than you originally sold for.