Can anyone tell me if the new mark to market rules being bandied...

Can anyone tell me if the new mark to market rules being bandied about are applicable to reits? Articles I read all seem to apply to banks. How universial are these rules going to be? I assume in U.S.A. helps MOF.
If they do apply and are broadbased it's no wonder the bears are getting scared and the shorters sh..ting themselves. Why destroy a solid well run, viable company over an accounting rule, it seems incredulous?
Jeff