I suppose that because the release of IE10 for Windows 7 next month is now a "preview" it won't be pushed by Windows Update. At some point, however, I'm sure that WU will push it.
I have some users of Windows 7 who use some proprietary software packages that in the past have had difficulty in keeping up with the latest browser revisions. Will there be an IE10 blocker kit available so that I can stop automatic update to IE10 until the proprietary software has been cleared to use IE10?