It appears that shadows are only casted by objects close to the camera. I'm not sure if it's a box or radius or what, but it'd be nice if we had a way to expand this area which determines whether or not an object casts a shadow. As it stands, I shadows tend to flicker on and off and moving the camera a miniscule amount to the side could make a shadow appear or disappear in a very noticeable way. Obviously shadows are graphically intensive, so some people wouldn't benefit from an enhanced shadow casting radius, but I could argue that if such is the case, you should disable shadows anyway.
As it stands, shadows seem incredibly awkward because of that appearing and disappearing. Most modern machines should have no difficulty with, say, twice as much shadows, anyway.