by boco » 25.06.2012, 01:59
If you select in the installer to install IE9, it is installed first and, following reboot, only the relevant IE9 updates are installed. The IE8+updates are still downloaded in case a user doesn't want IE9. When IE8 reaches end of life it will be removed from WSUS (like IE6 and IE7), but as long as it's supported by MS it is in their catalog and the updates will be downloaded.
Microsoft update catalog: http://catalog.update.microsoft.com/v7/site/
Windows Install media download: https://support.microsoft.com/en-us/help/15088/windows-create-installation-media