Borrowed a copy from a fried to see if it would work on my machine.
It won't. I meet the reqs, but my video card chipset is unsupported...which is too bad, really, cuz it's a nice card. Problem is, I can't upgrade without buying a whole new motherboard: I bought the comp just before AGP slots were mandatory and well before PCI Express. So all I have for upgrade slots is old-school PCI, and none of the cards Oblivion supports come in that flavor.
Of course, sooner or later, it will provide an excuse for an new CPU.