This abstract from a 2010 paper by Martin Hellwig sums up the debate about overhauling the financial system:
Whereas the Basel Committee on Banking Supervision seems to go for marginal changes here and there, the paper calls for a thorough overhaul, moving away from risk calibration and raising capital requirements very substantially. The argument is based on the observation that the current system of risk-calibrated capital requirements, in particular under the model-based approach, played a key role in allowing banks to be undercapitalized prior to the crisis, with strong systemic effects for deleveraging multipliers and for the functioning of interbank markets. The argument is also based on the observation that the current system has no theoretical foundation, its objectives are ill-specified, and its effects have not been thought through, either for the individual bank or for the system as a whole. Objections to substantial increases in capital requirements rest on arguments that run counter to economic logic or are themselves evidence of moral hazard and a need for regulation.
The bipartisan bill, Terminating Bailouts for Taxpayer Fairness Act, sponsored by senators Sherrod Brown, an Ohio Democrat, and David Vitter, a Louisiana Republican, is a courageous attempt to address the undercapitalization that led to the global financial crisis. Abruptly raising bank capital requirements would lead to a credit contraction if introduced in isolation, but the Fed is quite capable of adjusting monetary policy to offset this and a suitable phase-in period would give banks time to adjust. What is important is that we get to the point where banks are properly capitalized to deal with any future instability.
Read the full paper at Capital Regulation after the Crisis: Business as Usual? | Martin Hellwig, July 2010.