Just as an update to my specific problem, I brought it in to the Apple Store today, and using an external drive to boot in to first, they were then able to get my Mac Pro to boot in to 10.7.5 with that drive being the only one in the system, incorrectly diagnosing my other hard drive as bad. I brought it home, and within minutes, the display had blurry lines throughout, the colors were off, and quickly moved to a full blown lock up. I then tried to install 10.7.4 from my bootable flash drive, however, even with 10.7.5 completely wiped off my drive, the display problems persisted.
Purchasing a new video card ($250) from Micro Center fixed the problem, and I was then quickly able to restore my system from a Time Machine backup (which was on the drive the Genius Bar erroneously diagnosed as bad). Now I'm up and running on 10.7.4, and won't be touching 10.7.5 again.
While I'm not sure how an OS software update could brick a video card, I do know that the problem I had started after restarting from the 10.7.5 install, and then persisted to have problems (and make the computer unusable) until it was replaced.
Purchasing a new video card ($250) from Micro Center fixed the problem, and I was then quickly able to restore my system from a Time Machine backup (which was on the drive the Genius Bar erroneously diagnosed as bad). Now I'm up and running on 10.7.4, and won't be touching 10.7.5 again.
While I'm not sure how an OS software update could brick a video card, I do know that the problem I had started after restarting from the 10.7.5 install, and then persisted to have problems (and make the computer unusable) until it was replaced.