So after some more investigation, I'm getting closer to figuring this out and would appreciate anyone's insight/opinion if you've got any ideas.
Friday night, I restored a windows system image from before the issue began and it fixed the problem immediately. Afterwards, the only significant changes I made were to re-enable a custom fan profile in MSI Afterburner...I did not reboot the system after doing this. The system worked great all weekend, but on Monday I installed some Windows 7 updates that required a system reboot; afterwards, the issue returned.
This morning, I formatted the hard drive and installed a fresh copy of Windows 7. For my first testing, my system consisted only of:
(1) Motherboard/Chipset Drivers
(2) NVidia 296.10 Drivers (Graphics Drivers/Physx Only)
The issue was not present and my performance was normal (~110 fps in SWTOR with full 99% GPU usage). I saved a backup image and then added all of the utilities I normally use:
I set up a custom fan profile again, tested everything, had no problems, and saved another backup. However, after doing some other work that required a reboot, I found that the issue returned. In retrospect, I also remembered that Wednesday morning of last week was the first time that I setup a custom fan profile, and I did not reboot the machine again until Thursday night (the issue first began on Friday morning). I'm restoring my last (pre-Precision) backup in order to test this, but my strong suspicion is that somehow setting up the custom fan profile is causing the video card performance problems. Has anyone ever heard of anything like this?