Obviously, bitcoin does nothing to prevent banks from doing what they have always been doing. A lot of clueless people think Bitcoin is a "libertarian solution" to life's economic woes (ironically, this last 9 years up to 2009 have been a classic example of how libertarian economic policy, e.g. deregulating everything, is a horrible idea resulting in speculative bubbles, just like bitcoin's current price is a speculative bubble).
On the contrary, I think it was the government's hand in the market that caused speculative bubbles. Specifically I'm talking about subsidization of home loans through the tax code, and manipulation of money supply/interest rates that lead to a lot of people buying houses they otherwise could not have afforded. The government, if anything, failed to regulate the natural consequences of its own actions.