Quite a common use case for Linux is where PC's are installed on computers without internet access, or where internet access is very expensive. So, enter PackageKit. You insert a CDROM or USB pendrive with updates on. The following UI appears: 
You click “yes” and then the update icon appears as if you were online. You click “Update system” and then the update proceeds as if you were online. Plus, because the local media is an actual repo, you can also use the Add/Remove software tool as normal. Nothing is in git master yet, although I've got a local branch that I'll probably merge after 0.1.10 is released. Comments appreciated.
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hughsie
Richard has over 10 years of experience developing open source software. He is the maintainer of GNOME Software, PackageKit, GNOME Packagekit, GNOME Power Manager, GNOME Color Manager, colord, and UPower and also contributes to many other projects and opensource standards. Richard has three main areas of interest on the free desktop, color management, package management, and power management.
Richard graduated a few years ago from the University of Surrey with a Masters in Electronics Engineering. He now works for Red Hat in the desktop group, and also manages a company selling open source calibration equipment. Richard's outside interests include taking photos and eating good food.
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I insert media and I would like to view the package updates before confirming that I trust it. Can you change the UI to support that? Sometimes I just need to distribute a set of packages to a friend that does not have a net connection. It is not a service package (ie) a set of updates to existing software. You probably shouldn't call it a service pack in that case.