It's a hassle to get to Tyson's Corner without a car. Both the East and West Falls Church Metro stops (orange and blue lines) have buses that go into Tyson's Corner, but all of this seems a bit much. Currently, there is project to add a new rail line to the D.C. Metro system that would make this trip more convenient.
According to Washingtonpost.com, the proposed "silver line" is still in its planning stages. The first phase of the line - to Washington Dulles International Airport - is slated for completion by 2011 with the second phase - to Loudoun County - done hopefully by 2016.
The new silver line will have three stops in Tyson's Corner and will serve as the rail line for Washington Dulles Airport. There have been discussions of Washington Dulles having its own line since the late '70s but only recently did the plan begin to be set in motion.
Currently, there is only one D.C. Metro stop for an airport, at Reagan National Airport. To get to Washington Dulles, one must get off at the West Falls Church Metro stop and take a bus the rest of the way, once again adding more stress to the already complicated process of air travel.
The proposed silver line will include all stops along the Metro's orange and blue lines and will break off at the West Falls Church station, with stops in Tyson's Corner and at Washington Dulles Airport.