...But it is higher than where it was? And after people cash out the price will stabilize. Once that happens business's like mine (openspacemovement.org) will feel confident enough to start accepting bitcoins as a form of currency. Once that happens the value will become incalculable!
It will never stabilize, and you summarize why pretty well with this post. The Bitcoin price will continue to rally and then crash forever. When people think it will go down they will sell, hoping to get cheaper coins later, which pushed the price down. Then, when it has fallen so far that enough people think it can't fall much further it stop falling. That will put people in the "value will become incalculable" modus again, and we'll have a new rally which will last until the price has become so high that more money are being pulled out of the market than added.
But what your saying doesn't take into account bitcoins eventual adoption as a true currency, business's accepting it across the board, or the finite number of them which once are completely mined will eliminate much of the mining pools and other BS that are bringing this commodity down.