If you have the UAC prompt set at ANYTHING other than the lowest level, then it will prompt you for a change (if that change is to a LOWER level than what it is currently at).
I agree that UAC should not have a "whitelist" for Microsoft apps, but don't bitch because they didn't fix it. They fixed the issue where it wouldn't prompt you if you were on say level 2 and wanted to go to level 0 (IE: turned off).
FYI -- the default setting, while not ideal, will still keep most problems at bay.
Try it for yourselves -- set it on "Notify me only when programs try to make changes to my computer (do not dim my desktop)", and then try to set it to the one below it "Never notify".
You WILL get a prompt...
-- Brian