"The list of updates you selected has been successfully approved, and the updates are available for distribution to your clients."

I have my test client set up to update from the SUS server everyday at 14:00 hours. Everyday at 14:00 hours the AutoUpdate Globe pops up because I have the client set to Notify Download and Notify Installation. When I open the Globe up from the Taskbar I get a message that the following updates are ready for me to download. And when I attempt to download the updates it just sits there. No updates. I've done everything but chuck the machine out of a 3rd storey window.

From the microsoft.public.softwareupdatesvcs newsgroup
"And when I attempt to download the updates it just sits there."

You mean the AU window sits there, or does it close and the AU icon sits there? Or is the AU icon even present after you click on Start Download?

It sounds like the download itself is failing. AU doesn't do that actual downloading of updates, but instead passes a download job to BITS (Background Intelligent Download Service). If you take the BitsAdmin tool from the Support directory on an XP CD, and after clicking on 'Start Download' go to a Command Prompt and type:

bitsadmin /list /allusers /verbose

it may give you information on what it is trying to download and why it is failing.

One quick thing to check is to make sure that you have anonymous access set on the IIS root of the SUS server, and the '\SUS' folder (especially the '\SUS\Content\Cabs' folder) has access to Everyone. BITS attempts to download from that '\Cabs' folder and if it can't get to it or access it, that could cause problems.