Why is Mikhail Baryshnikov working on so many projects? “Just about everything he does professionally — including disbanding his White Oak Dance Project after more than a dozen years and taking a non-dancing role in the TV series “Sex and the City” — is intended to support his visionary Baryshnikov Arts Center, located in the top half of the new six-story W. 37th Arts complex in New York. Scheduled to open this fall, the complex houses three off-Broadway-style theaters (one of which Baryshnikov plans to acquire by 2006) and, above them, studio, conference and office spaces that he already owns and intends to use to make New York City more art-friendly for young people.”