NBC today announced the stop and start dates for hosting duties on The Tonight Show in 2009: Jay Leno ends May 29th, and Conan O’Brien starts on June 1st. Meanwhile, Jay pulled a Jimmy at the TCA today. Like Kimmel did at ABC’s presentation last week, Leno showed up in costume — bald cap, goatee to hide that big chin, black glasses — and sneaked into the back of the room. (Photo, right, released by NBC.) Then he began asking questions of the NBC bosses like whether Leno would be paid for the whole year even if he’s only working for six months of it. (The answer was yes.) The TCA press laughed and applauded. Then again, they’re easily amused. An NBC source told me that the bit was Leno’s idea because Jay “felt bad” about making that announcement he was “done” with NBC and claims he was “misunderstood”. Sure. Transcript of Leno’s exchange.