Say what you want about Bill O'Reilly (and I know you will), but the man has no qualms about stepping into the ring with those who disagree with him. He's appeared on both The Daily Show and Late Show with David Letterman, so why would he be shy about appearing on The Colbert Report, a show that, in many ways, owes its existence, or at the very least, its aesthetic, to The O'Reilly Factor? I've said here before I actually liked O'Reilly before his ego outgrew him, but I still love to watch his appearances on Letterman. As annoyed as Dave seems when O'Reilly is on, you know deep down he revels in those confrontational moments.