The one mile hike (IMO) is not worth the time or effort to get to. I mean, if you're a hardcore gamer desperate for a fix while you're away from home..ok.
But if you were just curious and were just planning on stopping by to take a looksee, spend your time taking in the sights and scenes in D.C.
The White Flint Metro station is in the heart of D.C. suburbia with little more than strip malls, regular malls and all that is over-congested in our little nook of the world. Like I said, take a stroll down on The Mall in downtown D.C, see the White House, Capitol, the Jefferson and Lincoln memorials. Go to all the museums on The Mall. The best ones (IMO) are the National Art Gallery, Air & Space Museum (*warning* TONS o' KIDS!), and the Museum of Natural History.
Did I mention the fact that all of the above are F-R-E-E!