On the SharePoint team blog, you can find a more detailed post announcing the release of the December CU and providing detail on a new package that we are shipping from this point forward: http://blogs.msdn.com/sharepoint/archive/2008/12/17/announcing-december-cumulative-update-for-office-sharepoint-server-2007-and-windows-sharepoint-services-3-0.aspx
While the packages are physically large, they do include everything. It doesn't hurt you if you don't have something installed, it is simply skipped. We believe that this will greatly reduce the complexity of managing the patching of your systems. We are continuing to work to update content in general in this area and will specifically be making an update to the deployment documents in January to reflect this new methodology.