Judging by several posts regarding a future 997 Carrera 4 Turbolook, it seems that there will be one.
Personally, I wouldn't put my money on it.
Porsche didn't make the C4 and C4 S 44 mm wider in the rear without a reason. The 997 Turbo is rumoured to get the same body with the well known side air inlets.
Much wider is hardly possible, Porsche can't build a car as wide as they wish, they have to take a few "rules" into consideration too, not to speak about car wash installations, etc.

To be honest, I never heard even the slightest rumour of a C4(S?) Turbolook. Of course it can't be excluded that as soon as the 997 Turbo shows up, Porsche offers a car with a similar look without the side air inlets. But after I saw one of the current 997 Turbo mules, I doubt it. In my opinion, the 997 Turbo will look like the 997 C4S with five visible differences: side air inlets, slightly different front bumper, rear bumper with air inlets, retractable rear wing similar to the 996 Turbo and the bigger front brakes.

So if people are waiting for a "Turbolook", well...