There's a discussion on istock at the moment about 3D renders, in which the chief 3D admin, Mark Evans, has said that they intend to segregate 3D renders out into a separate section (or at least be tagged as 3D renders). One or two people in that discussion consider it important to know if an image is 'real' or fake.

I'm in a subversive mood at the moment. My port on istock is small, but henceforth I intend to follow this process with my photos:
set up a plane in Blender orthogonal to the camera, with the same resolution as the photo
map the image to the plane as a texture
use the compositing nodes (equivalent to adjustment layer on PS) for PP
render
upload as a 3D render (which it will be).

As if photography is reality...

like the argument about digital photography is too much photoshop

aside from some pj's when has commercial photography ever been about reality??? pic of abraham lincolns head on another body, hours in darkroom, even soft focus lenses etc etc. not to many black & white or sepia landscapes around (not to mention cross processing