It's one of those user point of view things however. I have UAC on, on both my home and work computers, and it doesn't bug me (literally) much, when setting up a system you can expect it a lot, especially when no applications have been corrected to work
as applications should.
But I can see from the end users point of view why this is frustrating, I think theres an aspect of illusion in Windows up to now, that the computer does only things they ask it to do, and it should know exactly what was sent by a user request, and exactly
what the user agreed to.
Users will start to wonder why they have to confirm "everything" they do.
Of course, most people here know the story of Windows, and why UAC was created, and why it probably is the close to the best solution to start migration of Windows in to a more structured and secure platform.
But again, its that thing of users not seeing this; but I have to say, my parents have Windows Vista Home Premium and I've explained UAC to them in simple terms, and they don't seem at all bothered by it.
UAC also reminds me every so often that it's useful to me, silent installs triggered by other applications etc.
Now I can tell those damned silent installs where to go! (if I want)