Howard Stern/Stuttering John Question

[IQ89]

I stopped listening to the Stern Show after they replaced Jackie with that obnoxious A-hole who can't shut the ---k up, plus I don't have that satellite radio thing to hear the new show. Anyway, I noticed "Stuttering" John on the Leno show around a year or so ago, and was wondering how that all came about? Was John let go like Jackie was, and then picked up by Leno? Was John stolen by Leno? What does Stern think about John on the Leno show? I notice Howard doing the talk-show circuit, but I haven't seen him do Leno. Is there a bit of a feud going on?

Thanks for any update.

PS. Why hire John on the tonight show, and then not send him out to do his interview shtick? If all they're gonna do is have him say, "Heeeere's Jay Leno," they should at least have him stutter the line once in a while.