Ed. Note: This is a rather clever way of defeating the dreaded QuickTime registration dialog. However it does require access to the package before deployment. It also is a good example of some of the things that pre and post-install scripts do within packages.
Here at my University I deploy the QuickTime updates not via SoftwareUpdate but with rsync, cron, and the QuickTime.pkg. You can edit the preflight script inside the package where you find the following text.
"# Marketing (aka Amy Fazio) sez we don't need to bring up the registration dialog anymore # but let's just comment it out for now in case they change their minds. - duano! 3/16/04 # ... see, QT BRB did change their minds on this. Putting it back until Gibson - duano! 3/17/04 # Putting it back in again for Legal reasons (QT5Pro users need to know they're gonna lose functionality)."
Delete the dialog crap underneath and there you go.