If this were a stock chart, I might agree with you, but it's not. It's a new medium of exchange, the likes of which we have never seen before. Why, then, does it follow that this is also a bubble? Sure, some folks will want to take profits, but consider:

1) Speculators want the exchange rate to increase, and to increase for as long as possible. Speculators will hold as long as the price trends higher.
2) Merchants want the exchange rate to increase. They will take new approaches (for instance, sell products for lower than their value in anticipation of an exchange rate increase).
3) New users want the exchange rate to increase. The higher the price, the more interest, the more users of the new currency.
4) As the market cap rises the rate eventually reaches a balancing point. It won't fluctuate by many dollars per day, but instead by fractions of a cent. When its stable, more merchants will enter the market, and users have less incentive to cash out since they can finally take advantage of the true benefits of the new currency: anonymous, global, simple payment processes. And all this without the tax implications.

I anticipate corrections but an upward trend until some (much higher) market cap is reached.