Well, kinda. A lot.

We use AU (w/o SUS/WUS) to deploy Critical Updates (and I'm not alone according to polls taken by myITForum). I'll have to turn off AU because we haven't finished our assessment of the impact that SP2 will have on our XP systems. This means that it will effectively break our current patch management system.

We are in the process of rolling out SMS 2003, so we do have something in the works. What I may do is write some GPO scripts that will continue to allow AU to run on all non-XP OS's and shut it down for XP.

My opinion is that this is very bad mojo on Microsoft's part.