Although I'm not a huge fan of speculating about Mercedes models several years from production, that hasn't stopped the industrious gentlemen of Auto Bild from doing exactly that. The publication recently dedicated an entire article to the future Mercedes CLS, providing both future renderings of the four door coupe and a number of design, equipment and engine details.
Of course, the entire article is based on pure speculation at this point, so take it all with a grain of salt. My main reason for directing you to the article was simply for the fact I enjoyed the above-depicted Huckfeldt rendering, although the front of the view leaves much to be desired (see below). As to whether or not either bears any resemblance to what the next CLS will actually look like is an entirely different story, but look at the bright side: the next model should debut around 2011, so you only have another three years to wait to see if Huckfeldt's vision will come to fruition.
To learn more about Auto Bild's vision for the future Mercedes-Benz CLS, head over to their website where you can find the full article translated from German for your reading pleasure.