An interview with President Obama from this week, provides a good summary of the problems that Obama sees with Wall Street and the changes that have been made as a result of the financial crisis.
Right now, if you are in one of the big banks, the profit center is the trading desk, and you can generate a huge amount of bonuses by making some big bets; you will be rewarded on the upside. If you make a really bad bet, a lot of times you've already banked all your bonuses. You might end up leaving the shop, but in the meantime everybody else is left holding the bag. Now what we've been able to do is to try to prevent taxpayers from being the folks who are left holding the bag.