Partrick is the artist and a very good one at that!!
However, I disagree completely with his interpretation. IMO this is VERY much just a massaged C5 body - it looks nice, but is not representative of the design direction the C6 will go.
It is too smooth in the wrong places. The C5's oval theme will be replaced by the "V" look and the Circle - see the generally accepted new emblem. He has suggested the "V" on the body below the hatch glass, but not strong enough. Look for the C6 to have the shape of a "V" in the upper hatch glass itself that will carry into the roof. Remember the hood shape on the Black NM car? It is a wide "V" shaped power buldge that, I suspect, will terminate with a reminder of the more narrow C2 front "point" where the emblem is placed.
Also, there is no need for the bulging lower, outer rear - there are no muflers there now so that would be waisted fender weight.
Also the tail lights, whatever final shape they take, will be flush with the body, or possibly stick out a bit. Cleaning will be easier. A little thing, but promised by Hill.
Partick's wheels are wrong. A carefull look at the cammoed black wheels reveals a spoke that's just a little wider than the current C5 wheel (maybe a third as wide as the '97) with a small '97 type "indent" near the rim. The spokes will be narrow enough to show off the new hot calipers and discs. If you like black, buy some spray paint 'cause they won't be delivered that way.
Oh, the side marker light is wrong too. Front and back will be round.