Rem Koolhaas’s design for the theatre that will anchor Dallas’s grand new Performing Arts Center has undergone its first round of retooling, and the results are impressive, says David Dillon. “The Wyly looks like nothing in the Arts District, or anywhere else for that matter, which is just fine with the adamantly acontextual Mr. Koolhaas. He likes buildings that are mysterious and hard to place, that might be anything and anywhere.”