According to Anthony Randazzo at Reason (amongst many others)
Third, the SEC should suspend the "mark-to-market" accounting rules for long-term assets that are driving firms into bankruptcy. Essentially, these regulatory rules are forcing firms to value their assets at much lower prices than what they would be worth long-term. The intent of mark-to-market regulation was to keep firms from overvaluing themselves and deceiving investors. Instead the law has artificially devalued financial institutions as a whole, which hurts their investors. As Steve Forbes noted recently, "The mark-to-market mania of regulators and accountants is utterly destructive. It is like fighting a fire with gasoline."
Not so, say the ISAB (surprisingly :) [Note: pdf link]