An English friend of mine got his first dose of Jay Leno and Conan O'Brien last week, and commented that while Jay seemed friendly and confident, his "Tonight Show" replacement was more of a cipher. He wondered, "Do you think O'Brien will fit in?" That's the multimillion-dollar question. O'Brien has only taken over shows, and never originated his own. He spent 16 years remaking David Letterman's "Late Night" into his own comedic image, but this time, he's walking into an institution. NBC's "Tonight" is bigger than O'Brien, which means he's got to conform to expectations -- while trying to give...