Last week Microsoft was all set to free the low-end Vista Home Edition to run virtual machines like, oh, with Parallels' software on the Mac or VMware. Then it changed its mind, saying it had "reassessed Windows virtualization and decided that we will maintain the original policy announced last fall." No reason why.

Microsoft has previously claimed there are security risks though the $299 Vista Business and $399 Ultimate are free to run as guests.

David Greschler, Microsoft's director of virtualization strategy will deliver a keynote presentation this week at the Virtualization Conference & Expo in New York City and expected to answer questions from the press covering the conference.

Server virtualization has caught the attention of many IT professionals for the cost savings and agility afforded via consolidation, business continuity and test/dev. However, Microsoft customers and Microsoft IT have moved beyond the traditional datacenter uses of virtualization and have begun innovating around the desktop and alternate software delivery models. Virtualization will help the industry accelerate the move towards a services-oriented model by enabling a broad set of offerings – from the OS to applications – to be portable and, therefore, available on demand. Greschler will provide examples and best practices of how organizations are leveraging virtualization beyond the datacenter.

Speaker Bio: David Greschler is the director of virtualization strategy, System Center division at Microsoft Corp. He is a director of System Center marketing, and is focused on virtualization management tools for the desktop and datacenter. David came to Microsoft with the July 2006 acquisition of Softricity. Prior to joining Microsoft, he was co-founder of Softricity, developers of SoftGrid and the originator and leading vendor of the application virtualization industry. With more than 20 years of pioneering experience in the computer field, David has held various positions at the MIT Media Lab and The Computer Museum, and holds numerous virtualization patents.