The capability to over commit memory is an evident advantage that VMware has over competition.
Marketing departments, partners, and even customers engage endless debates about its value and usefulness in every scenario.
Microsoft actually equipped its hypervisor with memory over commitment capability and that was ready to appear in Hyper-V 2008 R2.
For some reasons anyway the company pulled the feature during the beta phase without disclosing when customers would finally get it.
Microsoft is already working on Windows Server 2008 R2 post-RTM builds and Internet abounds of leaked screenshots about those. One of them, published by Softpedia and related to the build 7700.winmain.100122-1900, reveals that Microsoft has reintroduced Dynamic Memory controls in the Hyper-V control panel:
This doesn’t really mean that the feature will appear in the next Windows Server 2008 R2 service pack or in Windows Server codename 8, but its presence in this build confirms that Microsoft is getting ready to reintroduce it.