The New York Times had an article discussing the filing of the liquidation plan for what remains of General Motors.

When General Motors filed for bankruptcy back in June 2009, the "valuable" assets were sold to a new entity pursuant to a 363 Sale that became the new GM. The remaining assets consisting of contaminated and surplus facilities remained with Motors Liquidation Corp (MLC). According to the article, many of the 90 sites are contaminated and will be placed into an environmental trust that will be responsible for remediating and then selling the sites to developers. The article goes on to say that the Trust will be funded with $536MM of TARP money from the Treasury Dept along with an additional $300MM for demolition and security. 

A trustee has not yet been selected to manage the trust.  In the interests of full disclosure, I have been one of the candidates under consideration for the trustee position and therefore am limiting my comments to publicly available information. However, the plan of liquidation is a public document that is available from the United States Bankruptcy Court for the Southern District of New York.