Banks have 2 key functions: 1. Taking deposits and lending them out again. i.e. creating money through the credit creation process. 2. Providing money transfer capabilities.

positvemoney.org runs a policy campaign which makes a compelling argument for a separation of these two functions as a response to the financial crisis. One of the arguments is that when the investments of banks fail, our ability to transact fails with them. Not exactly a resilient system.

There are a number of existing open source projects to create libraries and protocols to generically provide money transfers. http://opencoin.org (disclaimer: I am involved with this project) http://opentransactions.org http://opencoin.com - open source but very much commercial

Those who say bitcoin is addressing these functions are misguided. Bitcoin is arguably a currency tightly integrated with a transaction technology. In theory the bitcoin transaction technology could be re-worked to be useful as a library for money transfers (non-anonymous). I imagine that would be a significant amount of work.