Mark to market accounting- a 'clarification' from the SEC

The SEC and FASB have made a recent announcement on mark to market accounting.

"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."

Though that's what managers can do already. SFAS 157 allows 'mark to model' accounting. Prof Bainbridge has already made this observation.