OK, here's my 2 cents worth. I've worked with a number of large companies over the years and have seen the issues caused by having users as local admins and having no local admin permissions given to users. My opinion is that you should see a drop in help desk/support issues by taking away admin privaleges. For the most part (but definitely not in every case), the average user can cause more harm than good with admin privalges. They read something in an article or hear something in a conversation and change settings on their machines without really knowing what the impact will be. And then there's the issue of approved software (if you have such a policy in place). The list can go on and on.
A good way to justify the action of taking away local admin privaleges is to document the time spent by help desk/support people when dealing with any issue caused by having users with local admin privaleges. Keep track of this for a month or so and you'll get a good feeling for the cost vs benefit of having users with these privaleges. In almost every case I've seen the results have been eye-opening.
You will certainly have users that will complain if you implement this strategy. But when you think about it from a management standpoint, why would a user really need admin privaleges? If the technology dept sets the machines up properly and maintains them properly, what else does a user really need? It usually boils down to a state of mind. The user thinks that they are no longer in control and it hurts their pride. The best thing to do is commnicate throughly and dispel any and all questions which the users might have. The first little while after implementing a policy like this is the worst because every issue that comes up will be a point of contention with some users who will use it as an example of a bad decision on your part. But, after some time things will smooth out and most users won't even notice.
Nuff said.
Cheers.
RW