Anyone know an actual download on the website outside of Windows Update that is requiring this? I was poking around on the site and could still download some XP specific things fine via Safari on my OS X box.

My biggest concern if they do lock this down is being able to download patches for people not on broadband connections. I have frequently grabbed the bigger patches needed for XP to then take via USB storage to my mothers laptop, or to use at work on multiple machines. Somehow, I expect a workaround to all this, one Microsoft provides for all the IT support people out there. 3rd parties have reportedly already worked around it anyhow.