To automate the patch process is one of the demands to achieve Private Cloud. Of course because of the many dependencies in the different environments that is not completely possible. But this automation can be started from the Hyper-V clusters. On the link below you will find script created by Jason T. Ruiz that automates the patching process using SCVMM, SCOM and WUInstall. Click on the link and patch.

http://gallery.technet.microsoft.com/Update-Hyper-V-Hosts-via-71b86c1a