Since the big banks and Insurance Companies (such as AIG) have written most of these contracts, and since there are potentially $Trillions of dollars in assets that cannot be valued properly, and therefore cannot be cashed by the buyers, affecting the health of the entire global financial system, don't bet that the administration will have an easy time convincing these entities to list their contracts on open exchanges.
However, if I don't miss my guess, the Obama administration will make these changes, or at least a strong oversight regimen, probably this year.
Though this transparency may be good for the overall economy, it may not be very good for some big players whose financial future may depend on keeping these contracts from the public eye.
Update June 4-09 New York Times
Update on the Obama Plan July 24th-09 at Breaking Views .