The installs went perfectly. So good, in fact, that I even ran the CompCln.exe utility that's included in SP2 that deletes all the backup files created during the SP2 installation process. No turning back now, and why would I? Everything installed just fine.
...until I got home to my server and found that the display, keyboard and mouse were unresponsive. I RDP'd into the server and restarted it. Fail. Started in Safe Mode. Fail. Last Known Good. Fail. Fail. Fail.
Not relishing having to rebuild my main Hyper-V server, I gave it one last shot by starting up in Safe Mode Command Prompt Only mode. I suspected it was the VGA driver, so I changed to the Windows\System32\Drivers folder, renamed the ATI video driver (aitkmdag.sys) and restarted. Success! The server started up normally using the Standard VGA Graphics Adapter. Crisis averted.
I can't blame SP2 for this mess. I attibute it to the buggy beta ATI drivers I had installed. In any event, I'm glad I got the server up and running without having to rebuild it all.