It was all about the couch. Reaction was plenty upbeat for James Macdonald’s direction of “Drunk Enough to Say I Love You?,” the political satire by Caryl Churchill that recently played the Public. But people really went bananas over the floating couch on which the entire play was staged.Macdonald, whose Manhattan Theater Club revival of Churchill’s “Top Girls” bows May 7, is appreciative but wants it known that, “It’s now over with me and couches.” The former associate director of London’s Royal Court has a history with couches. In “Dying City,” he caused one to migrate around the room to signify the uncertainty of relationships. In “A Number” (also by Churchill), he collaborated with set designer Eugene Lee on a way to examine the characters “in scientific, almost forensic detail” so auds “would be looking down on two guys on a couch that was like an operating table.” Macdonald would now like to apply his passion for new forms to the classics. Restoration comedy, perhaps, or Greek tragedy. “After 15 years of doing new plays, the world of classical theater is looking like a great big sweet shop to me,” he says.