First of all, don't double post.

Second of all, Conan was publicly promised the Tonight Show five years ago, which he started in June of 2009. Six months into his time as host, NBC decides that due to the Tonight Show's poor ratings and Leno's terrible ratings in his prime time slot, they wanted to get Leno back into his late night slot, where he'd flourished, and they would push the Tonight show back another hour. Conan decided that that would disgrace the Tonight Show name, and opted out. A lot of people (including myself) feel he got screwed out of the job.

And by the way, Conan never said he got screwed. The man interviewing him asked if he felt he got screwed, and Conan said no. Here's a video of the interview and the transcript if anyone's interested.