Update:
Unfortunately, I had alot of work to do last night (actually I'm pretty busy for the next month) so I didn't have time to properly spend with oblivion, but I can give you my first impressions:
THIS GAME ROCKS.
I spent 15 minutes making a character, and the remaining 15 minutes I had staring in awe at the amazing graphics, detail, and minutia of the game world.
I never even got outside of the dungeon yet, but the framerate with my X1800 was SPECTACULAR. Smooth as silk... I was really surprised by that. But as detailed as the interiors are, this means nothing until I step outside and see how the system deals with the crazy amount of outdoor detail.
Still, I'm really wowed by this game.