It has been virtually completely restored, down to the legacy plants in the garden, the slave quarters, and the distillery. It is well worth a visit and a contribution by anyone in the DC area on vacation or otherwise. Went there a few years back and donate ever since. They even have a boat ride/tour on the Potomac leaving from Washington's dock. It is a great patriotic landmark, without any Gubbermint support or interference.
I was there last Monday, and one of the docents was speaking about JA Washington III and his last few years there. Evidently, he had become bothered by all the people stopping there by carriage or boat and knocking on his door to see the place. He also was in not very good financial straights, so it was hard for him to keep it maintained.
But, God Bless the Mount Vernon Ladies Auxiliary.