Unless you've been hiding under a rock, you probably noticed that the final RTM release of Hyper-V was made available today for Windows Server 2008. If you haven't tried Hyper-V yet, you've got to check it out - it's pretty impressive. Now that it is RTM, you no longer have an excuse :-)
John Howard posted a blog entry explaining how to inject the final Hyper-V update into a Windows Server 2008 WIM; read more about that at http://blogs.technet.com/jhoward/archive/2008/06/26/deploying-windows-server-2008-with-slipstreamed-hyper-v-rtm-part-1.aspx. For those of you who are familiar with Microsoft Deployment Toolkit, you probably know that there is an easier way for Lite Touch deployments. Here are the steps:
That's all there is to it: MDT 2008 will automatically inject the appropriate updates into Windows Vista SP1 (x86 or x64) and Windows Server 2008 (x86 or x64) as part of the OS deployment process, so they will be there from the first boot of the OS.
Now if you actually want to install the Hyper-V role, you can do this using the "Install Roles and Features" action. Just add it into your Windows Server 2008 task sequence, check the "Hyper-V" role, and it will be installed.
You'll have to wait for the Hyper-V updates to be available through Windows Update before you can do the same thing with ConfigMgr 2007, but fortunately you won't have to wait long: those updates will be published in the next couple of weeks.