An SEC Press Release issued today offers a clarification that may relieve institutions that feel compelled to use "mark to market" or "fair value" accounting for debt securities as to which there is no liquid market (I'll try to just offer a neutral description here; other people at my law firm will no doubt be offering our clients more detailed advice on this topic). This is just one aspect of the credit crisis, but MTM has acted as something of an accelerant for the financial troubles of institutions holding mortgage-backed securities for which there is no active market. Some people, mainly on the Right, have argued that suspending MTM would give needed breathing space and eliminate the need for Treasury to step in as market maker and buy up MBS, while others have argued that loosening the accounting rules just conceals the problem and delays the day of reckoning.
Anyway, today's statement offers at least some clarification that companies need not be rigidly tied in to market prices where there's no market:
When an active market for a security does not exist, the use of management estimates that incorporate current market participant expectations of future cash flows, and include appropriate risk premiums, is acceptable...The determination of fair value often requires significant judgment. In some cases, multiple inputs from different sources may collectively provide the best evidence of fair value.
The statement goes on to note that distressed sales may also not be the best evidence of fair value and deals with other indicia of value such as broker quotes and methods of determining impairment of an asset (recall that unlike, say, the New York Stock Exchange, markets for debt securities do not necessarily have instantaneous public price reporting of all transactions). This is one example of how the regulators are now acting to use the tools already at their disposal rather than wait for Congress to give definitive guidance.
More analysis here.