MicrosoftHi Nathan Ziehnert,
If I understand your first question correctly, you are wondering how what Mike calls the "Smaller Update" could be smaller than the "Express Update". As far as the size of the content delivered to each client goes, I don't believe that Microsoft is claiming these updates to be smaller. In fact, if you look at the "Update size" graph, the bar for the new Quality Update is slightly taller than the bar for the Express Update. It sounds like the real benefits comes from the greatly reduced amount of data that needs to be transferred to and stored on the update servers, and the reduction in processing on the client.
As far as whether blocking access to Windows Update with a GPO would affect automatic corruption repair, I'd be interested to hear the answer to that as well.
