Complex sentence: Sher has served as Artistic Director at Intiman Playhouse in Seattle since 2000 and in 2010 he will be transitioning to his successor who will succeed him in 2011.
Split into simpler sentences: Sher has served as Artistic Director at Intiman Playhouse in Seattle since 2000. During 2010 he will begin the gradual transition to his successor who will succeed him in 2011.