Sounds like a plausible explanation Charles, apart from this problem started yesterday (before the new mac was released).
Plus, if I select the files from VersionTracker to download, it downloads at full speed, and I would have thought the files are still coming from Apple direct?
In fact, just to be sure.. I just went to Apples own download page, and its downloading just fine at full speed from there too. Its just via the software update control panel that it is horribly slow.
Same thing is happening on 2 different macs (both running 10.4.6)
I can't for the life of me work out why??