Fannie Mae and Freddie Mac are backing a potentially revolutionary new “fair value” accounting standard that’s being developed by the Financial Accounting Standards Board. The proposed Fair Value Option for Financial Assets and Financial Liabilities standard would amend existing FAS 115. FASB’s proposal could dissolve much of the turmoil and burden associated with the current accounting treatment for hedge transactions that has caused so much trouble for a number of financial institutions – including Fannie,…