Conan O’Brien wants viewers to be surprised when they tune into his final “Late Night” show on NBC (Friday, Feb. 20). The White Stripes will perform but that’s the only given as O’Brien wraps up 16 years and 2,725 shows in the 12:30 a.m. timeslot. “I’ll probably cry like a baby,” says O’Brien, 45, who was an unknown when he took over for David Letterman in 1993. He was severely criticized and nearly fired before connecting with America’s funnybone and becoming a late-night icon. It’s not so much a goodbye for O’Brien as a see-ya-later as he moves on to replace Jay Leno on “The Tonight Show” on June 1, and Jimmy Fallon steps into “Late Night.”