Slipstreamed installation points are good for deployment--provided you remember what you slipstreamed into them! You can slipstream service packs, hotfixes, and other patches into an installation point to make it easier to deploy a fully up-to-date and secure Windows platform. But if you do this often, you may forget exactly what's been slipstreamed into each installation point.
Here's a tip to help you out: once you've created the slipstreamed installation point, run Setup to install Windows on a box on your network. Then run MBSA 2.0 on the new machine to inventory what patches have been installed on it, save an HTML report from this, and copy it to the root of your slipstreamed installation point. Voila, instant documentation of what you've done!