Jay Leno will bring in more viewers than Kings. There are buttloads of Americans who find Jay he-larious. These people also tend to go to bed very early (hint hint). That's why NBC is giving up on several hours a week of original programming, this is easier. Just like intelligence-insulting reality shows are easier.
I think Kings would do better on a cable network like SyFy or FX, but I have to admit I thought it was a bit boring when I watched it. I am looking forward to testing out Community, V and Flash Forward on network this Fall. Love my DVR. I also watch Lost, Friday Night Lights, 30 Rock, the Office and recently Glee. Most of my non-sports TV viewing is on cable networks where everything seems to be better. Grooving on Mad Men and True Blood, just finished Weeds, Entourage and Rescue Me (all 3 getting a bit old but still better than most shows out there), especially psyched for the return of Dexter, Californication, Always Sunny, Breaking Bad, and Curb, and very intrigued about this: http://www.hbo.com/boredtodeath/