There are telephoto lenses and there are telephoto zoom lenses.
Then there are tele-extenders which increase the magification of a lens.
And … then there is this; three telephoto zooms in one lens.
However, it is still not available today, though originally planned for release in mid-2011.
Price tag (yet to be announced) may cause shock or heart arythmia.
http://cpn.canon-europe.com/content/news/telephoto_zoom_lens.do
latest update: http://www.canonrumors.com/tag/200-400/
(I would like to include the photo from Canon, but their website states: protected by copyright, kindly do not copy.)