Tysons Corner is, simply, the ultimate suburb. It could be a city - or a major metropolitan area - unto itself. It has more jobs, stores, restaurants and even cultural amenities than most cities. It's the best, worst, and most fundamentally complete vision of the modern suburban town that exists in the world today.
BeyondDC's not a big fan. Tysons is totally dominated by the car. There's no Metro access (although that will change in the not too distant future), and going anywhere by foot is totally out of the question. Even for lovers of the auto, Tysons is a congested mess, since the suburban model relies on a low density landscape, which, despite its development pattern, Tysons is not. (One BeyondDC reader chimes in to disagree: "it is possible to get around Tysons Corner on foot, if one is willing to take the effort and risk to do so". BeyondDC agrees, but submits that if walking calls for "taking one's life into one's hands to try to cross Route 7", that qualifies as a highly inhospitable environment for pedestrians. Never the less the point is made: Some people walk in Tysons Corner.)
Ironically, Tysons Corner may actually be the light at the end of Fairfax County's proverbial tunnel. Leaders there, faced with the undeniable problems of traffic congestion and geographic build-out, are starting to think a little more responsibly, and want to urbanize the Tysons area - to make it "Downtown Fairfax County". Maybe an impossible pipe dream, BeyondDC still thinks it's a great idea. The shear mass of development there has already made Tysons more dense than a typical suburban business district, and rising land prices have begun to force some mixed-use, although at this point that still means ground floor retail, not shared residential. The impending arrival of four Metro stations on the yet to be built Silver Line is already spurring not only land speculation, but upzoning on the part of the County. Likewise, residents forced to deal with ever increasing congestion and discomfort are beginning to see the successes of Montgomery and Arlington Counties, and have not only stopped fighting densification efforts, but are actually supporting them in many cases.