well the game is multi-processor or multi-core cpu ready
http://www.bit-tech.net/gaming/2005/11/09/elder_scrolls_4_int/2.html
"Oblivion will absolutely benefit from a multi-processor or multi-core PC architecture. These improvements have largely been driven by our optimizations for the Xbox 360 hardware. We have built a dynamic thread management system that manages processor load by our specific direction and by priorities. Portions of physics, AI, loading, audio, and rendering tasks can all be moved to different threads to keep the overall load balanced. The net result for the end user is a smoother experience." >> Thanks to xbox 360
Its also will be great with Unified cards like G8X and R6xxx
"The unified shader architecture definitely does help with the speed of shader processing. Plus, it's completely transparent to developers as the optimization all occurs behind the scenes on the hardware side of things. However, we've optimized our shaders so that the overall difference between Oblivion running on the Xbox 360, and Oblivion running on a fast PC with a Shader Model 3.0 card should be slight. We're locking the framerate at 30fps on the 360 so you probably won't see framerate improvements vs. the PC, but you might see a more stable framerate."
Also the game HDR / SM3.0 useage is awesome since you can see in the gameplay how the sun looks so real instead of big fat thing in the sky.
I think people will enjoy the game to fullest with a system like :
AMD X2 4400 or OC CPu like Opteron 165 @ 2.4Ghz +
2GB RAM
ATI X1900XT or G71 >> game will be more heavily shader reliant thanks to XBOX 360 so you may see a same benchmark result as in fear
THIS GAME IS THE NEXT FARCRY TYPE graphic

... Remember Farcry was 1st game to show off the latest GPU.. HL2, DOOM 3 , FEAR and others came afterwards.
Remember all the cry from people who couldn't run FARCRY

we may have something like that and i am really excited its an RPG game that will introduce the next level Type Graphic Standards not a typical FPS : )
Just one look at the forest in Oblivion and you know this game is going to be awesome.