This worked for me on 3 machines, all machins rolled back and did not go on to finish the sp1 install.
2 w7 ultimates 64bit and 1 w7 ultimate 32bit
nice work you clearly worked late on this.
I wonder if MS will "recall" the update from their global update service CDN, until this is resolved. I for one have denied the sp1 update on my update services server until im happy this has been resolved.
Thanks again, much appreciated, im sure you will end up helping millions with this post.