Christopher T. Dunworth has resigned as executive director of the brand new Mountain Laurel Center for the Performing Arts in northeast Pennsylvania, raising further questions about the viability of the center, which was to become the summer home of the Pittsburgh Symphony Orchestra this year. “Originally delayed from opening Memorial Day weekend by poor interior roads, the center will make its debut a day later than announced,” and the PSO has halved the number of concerts it originally planned to play there. Dunworth isn’t giving any reason for his departure, and Mountain Laurel officials have already announced his interim replacement.