At the end of May Microsoft recently expanded its support for the on-premises Windows Server Update Services (WSUS) and off-premises Microsoft Update facilities to a new virtualization product: App-V.
WSUS, formerly Software Update Services or SUS, is a free patch management platform offered since 2003 and quite frankly one of the best back-end product ever produced by the company.
At the moment the support only includes App-V 4.5 as reported on the WSUS corporate blog.