The hw jokes are dumb. Doom 3 ran well and scaled across a variety of machines. I expect that trend to continue with Doom 4. By the time it arrives, I expect even a modest PC's Doom 4 experience, will totally outclass the console versions of Doom 4.
At the time Doom 3 was out, I had a P3 with a GeForce 2 MX. which was far from the high-end systems. Still I was able to finish it there, obviously with all the detail turned down. I remember that the boss in Hell put my system to a crawl, but the remaining levels were less demanding and playable.
Same thing happened with HL2. I had to lower all the detail and had basically the same performance numbers as with Doom 3 on the same system.