Right now the exchange rate is 10% driven by commerce and 90% driven by daytraders.
I presume that commerce is largely driven by Silk Road and the likes, and given the other risks in that line of business, they can afford the volatility in the exchange as just a small cost of doing business, they are also largely unaffected by price as customers buy in and they sell our all in a short space of time.
Thinking about Bitcoin in terms of an "Innovation Adoption Curve" the economy is largely based on the Silk Road innovators and needs to glow more than 10x before the economy can be considered to have momentum. I think the boom bust market is a good way to distribute
BTC so i hope to buy when it hits a new low.