“Instead of focusing on another country, the major festival at the Kennedy Center next year will focus on another landscape: the terrain inhabited by artists with various disabilities, from deafness to diabetes, around the world.” Other 2009-10 season highlights include visits from the Mariinsky and the Bolshoi, Cate Blanchett as Blanche in Streetcar, Jennifer Higdon’s new piano concerto, and festivals of “Ballet Across America” and “Gospel Across America.”