Oh well . . . Hardware (CPU and GPU) and driver issues are going to continue to plague avid PC purists with all high end games because the devs have to try to please, and make their games run effectively on hundreds of different configurations. So . . games will continue to look better on some PC's than others.
I'm using an HDMI cable direct from a new slim XB360 to 42" Visio configured to 1080p and most of the graphics are breathtaking, crisp and quite detailed with only minor blurs on occasional textures when you get very close up. I understand your disappointment with how it looks on
your PC . . . it's not that bad on every PC . . . seems to be driver issues among some other things and some folks are reporting their issues in that area have been addressed and fixed. All in all that is why I do alot of my gaming now on the 360 . . . I build and repair PC's and have been gaming on them for over 20 years. My current gaming PC handles all the Crysis games, for example, very well yet I'm personally beginning to enjoy gaming on large HDMI screens through the XB360 way more than on my PC, and I'm saying is that Rage on the XB360 looks spectacular no matter how you slice it and how many ways you want to bash the "xbox standards" as you call it.
edit: adding following re: PC graphic problems - (clipped from Rage review feedback on Games Radar) hope it may help someone:
"on pc there are a few workarounds to the texture pop in and the lack of advanced graphics settings available. I did a quick google search: " rage advanced graphics settings" and found many options to improve the gameplay. After applying the new settings I had almost no pop in and greatly improved graphics crispness. I just wanted to share because it helped me enjoy the game that much more and still kept the 60 FPS. "