One of the key points of debate over financial institution regulation reform is how many different bank regulators there should be and the extent of their respective bailiwicks. Some argue that the number of regulators is a secondary issue. It's not. It's a first tier concern. A critical flaw of our banking regulation system is the ability of financial institutions to engage in regulatory arbitrage, which has a corrosive effect on the quality of bank regulation. As long as there are multiple federal banking regulators supervising essentially equivalent financial institutions there will be regulatory arbitrage, which will inevitably undermine whatever statutory framework Congress sets forth for financial institution regulation.
Currently there are four key federal banking regulators: Office of Comptroller of the Currency (national banks), Office of Thrift Supervision (federal savings banks), Federal Reserve Board (all bank holding companies and also state-chartered Federal Reserve member banks), Federal Deposit Insurance Corporation (state-chartered insured banks that are not Federal Reserve members). There's also the National Credit Union Administration (federal credit unions). There are some further twists to this mess, enough so that a good chunk of a banking regulation class is spent just on figuring out who regulates what entity within a bank holding company structure. This piecemeal structure is a regulatory system that developed out of peculiar historic circumstances; increasingly there is less and less difference in the types of financial intermediation offered by different types of financial institutions.