This is a pretty straight-forward process. Instead of beveling your mesh to created rounded corners (its rare to find perfect 90' edges in real life), you can quickly slap on a Mental Ray Rounded_Corners shader, and bake the result into a normal map using rendermap. A bonus to this, aside from how quick it is to do, is that you can also use an image to drive the strength of the rounded_corners, which allows you to create warped and chipped edges extremely quick.
Very awesome technique, thanks! Took me awhile to find but 3ds Max has the Arch and Design Shader for Mental Ray with the option to fillet the edges. What a time saver.
Excellent, hard edges are a real give away as to the quality of anything digital, so this is a real bonus to game quality.