Out is the first maintenance update for SketchUp 8, as announced by The Official SketchUp Blog. The big news is they fixed a projected shadow bug, a problem in the shadow calculating algorithm, that went unsolved for several versions.
Watch this good-humoured video made by the SketchUp team showing the issue, now fixed.
As one can see, when the camera passed under some shadows, other shadows would be displayed wrong, the full explanation from John Bacus, SketchUp Product Manager.
To update your SketchUp (PRO and free versions)
Windows: Go to Help/Check for Updates…
Mac: Go to Help/Check Web for Updates…