"We Know Which Songs Most People Want. We know there is a sizable audience for "Stairway to Heaven" so it isn't necessary for you to ask us to get it. We are already trying to get it."
I'm guessing Led Zep are tough to play ball with over their songs. I've heard that they didn't want their music used in films etc, but recently I've heard one or two - Immigrant Song springs to mind. So maybe they're softening a little and we'll get some Zep soon.
Maybe.