“In a new twist to the juggling act at ground zero, the city said yesterday that the Signature Theater Company would not be included in a performing arts center to be designed there by Frank Gehry, leaving the Joyce Theater, which presents dance, as the building’s sole resident. Estimates of the performing arts center’s cost were approaching $700 million, city officials said. Under the new plan, the center and a new Signature Theater are expected to come in at about $350 million combined.”