that IS a screenshot...photoshoped.
The scene.. models.. level.. gun and toilet can easily be taken by any joe if Half life had a death match mode. How ever the halos (glows), some smoothing, tochups are indeed photoshoped.. UNLESS they have done some seirouse coding and actually plan to add this in the form of an upgrade? the glows and such are not unlike that of what we have seen in some of the world war 2 games and starwars battleground. they used a shader to create a motion blur-esq over saturated image. I can see something like that easily being plugged into halflife (its a full screen effect that will work reguardless of game/d3 engine, its just an effect filter).. how ever the screen shot looks way well done, so I may just be dreaming here.