"With no in-game benchmark tool available, we had to devise one of our own. The best way to get reliable and repeatable performance was to run around the edge of Old Tristram, from the portal and back again, and record the frame rate with Fraps."
All this tests proves is that in Diablo 3 you can run in a circle, by yourself, on nearly any hardware. Even then, at 1920x1080 with highest detail, the 192-bit GTX 460 will drop below 60 fps. At 2560x1600 you would need a 7870 or GTX 580 to stay above 60 fps.
While running in a circle. Not fighting. By yourself.
Surely the game is relatively easy to run, but this test is hugely misleading. Once you add in four players, spells casting, the physics being put into action, with tons of mobs on the screen, you will be glad you spent some extra money on your hardware.