I don’t believe Jay Leno is moving to an earlier time frame. I think he is retiring altogether as a talk show host. On a side note, I like the Tonight Show a lot and I think NBC has made a huge mistake in choosing Conan O’Brien to be the new host. Conan’s humor and antics aren’t very funny, in my opinion, and he usually acts like a complete moron in front of the camera. When he takes over later this year, no more Tonight Show viewings for me.
This article here gives a little more insight into the Tonight Show changeover in 2009.