When the final numbers came in for last night's 11:35 (or thereabouts) shows, Jay Leno was in first place with total viewers, David Letterman was second and Jimmy Kimmel was third. All of those were pretty close. In the 18-49 bracket though, Kimmel had a solid lead. If he keeps doing that, he'll be around.
In an interview today, Kimmel said he expects to be the Number Three show in late night, largely because the others have such long histories, and that he'll be quite happy to be in that position. In answer to a question about taking viewers away from his hero, he replied, "I'm not killing Dave. We did not put a dent in his numbers. I don't think it will hurt him." I don't think anyone in the TV business, including Jimmy, believes that.