The financial system will continue to be a drag on economic growth because no one trusts it, and, for good reason.
Whether or not capital requirements are doubled or tripled, financial firms can, at any time, use the cover of proprietary information to manufacture and sell fraudulent securities. This means that there can be runs on banks, insurance companies, hedge funds, etc. at any time based on rumours, whether true or not, of fraud.
This fact that we can't see in real time and on the web what these companies are doing with our money makes the system incredibly fragile.
Dick Fuld, CEO of Lehman before it collapsed, said what happened to Lehman could happen to any bank. He's right. But his statement also means that Lehman wasn't to be trusted and that no surviving financial intermediary should be trusted.