According to Ben Lanka of the Journal Gazette (his Harrison Squared Blog):
Memorial Coliseum General Manager Randy Brown said he will have money in his 2009 budget to demolish the Wizards’ current facility on Coliseum Boulevard. But that doesn’t mean it will be crushed to rubble as soon as the first pitch is thrown downtown. Brown said he is looking to get a few extra events in Memorial Stadium next summer, including a possible concert. He said the stadium will remain open through next spring in case the downtown stadium isn’t quite ready for opening day. Brown said people should expect Memorial Stadium to fall in August or September 2009.