A year after the collapse of Lehman Brothers, one thing is clear: banks' ability to generate healthy profits will be challenged, as regulators impose tighter rules on them.
But the measures, which include raising capital and capping bonuses, are not likely to be introduced for months, maybe years, and even now regulators aren't in complete agreement over what they should be.
US regulators want banks to raise more capital to help discourage a repeat of the speculation that so damaged financial markets in 2008-2009. But some say that quality, not necessarily quantity, of capital is important.
"There is a need in the world banking system for more capital," Rep. Paul Kanjorski, chairman of the House Capital Markets Subcommittee, told CNBC during a visit to London to discuss reforming the global banking system.
Differences in philosophy, not only between the two sides of the Atlantic Ocean but also among European countries, means a complete overhaul of the banking system will be difficult to achieve.