Computer Specs
Core 2 Quad 9550 @ 3.5Ghz
8 GB DDR3 1333 Ram
2x GTX 560Ti (SLI) (285.65 Drivers)
160 GB Velociraptor (10k RPM)
X-Fi Xtreme Gamer
EVGA nForce 790i FTW
Windows 7 x64 Home Prem

Clean install, no mods, default graphics settings. From the character creation screen on, it's unplayable. I'm getting 7 to 8 FPS but the GPU usage is only 1 or 2% on both/either cards. All nVidia Control Panel settings are at defaults. No extra eye candy enabled anywhere. At one point, I played Oblivion on this system before with a pair of GTX 260s and it ran flawlessly even heavily modded.

Things I've tried so far:
-Wipe (Driver Sweeper) and clean install nVidia drivers (285.65)
-Wipe and reinstall Oblivion
-Disable SLI
-Disable HDR, Boom and AA
-Disable vsync

Thanks in advance for any suggestions!!

Try disabling SLI.

As noted above, I've tried that. No change. Thanks!

UPDATE: I also tried rolling back to an older display driver. GPU usage went from 1% to 20% but still only 7 or 8 FPS

Did you delete the Oblivion.ini file in My Documents\My Games\Oblivion? This file isn't deleted during a normal uninstall.

Done, but no change. I've done a Windows reinstall on this computer since the last time Oblivion was installed so it would have been a fresh .ini file anyway.

Whats CPU usage look like? What background processes are running?

Interesting development. For the sake of trying everything, I removed my Creative X-Fi Xtreme Gamer and uninstalled the drivers (audio service is no longer running) and I'm getting full performance. Apparently my audio drivers and Oblivion aren't playing nicely together? The drivers I was using were the most current for the X-Fi card. I'd rather not ditch my sound card for the sake of playing Oblivion, especially considering this same card was in the computer the last time I was playing Oblivion, before my Windows reinstall. Anyone ever hear of this conflict before?

Ok, so after spending a lot of time on this now, I've come to realize that I'm getting the 7 or 8 FPS and next to no GPU utilization whenever ANY audio is installed. I tried switching to onboard audio and I'm right back down to the low performance again.

Workaround: Went into Oblivion.ini and changed bMusicEnabled=1 to 0. Frame rate shot right back up to normal. svcks to have no music, but people say it's more immersive that way anyway. Oh well. Thanks to those who tried to help.

That shouldn't have that much of an impact on performance. I could see picking up 5 to 10 FPS by disabling music, but, that just seems strange..... are you using creative alchemy with your sound card?

I was. I'm on the Realtek HD now for the moment. I was googling around and saw someone with a similar issue and tried disabling the music on mine as well and that eliminated the performance issue. With the Creative card installed, I did a clean install of all the driver components before taking it out and that didn't change anything.