During my booth duty at the Failover Clustering booth, I must have heard questions regarding this topic about once per hour if not more.
The official stance: Microsoft does not support the virtualization of Exchange Server 2007 roles at this time. Why not? Well, Microsoft does not have a virtualization platform capable of supporting 64-bit virtual machines at this time. Hyper-V is not an RTM product. Whether Microsoft will change the stance once Hyper-V RTMs is another question, and I don’t have an answer. Also, keep in mind, Microsoft is not about to support a third party’s virtualization platform because they don’t have the control over it to properly support it and fix problems that might be discovered.
My point of view: Why would you ever want to do that anyways? Exchange and SQL are two services that really do require top-notch resources and sharing them on a server with other virtualized servers just seems counter productive to providing the best performance possible for two key business services.
OK, now that I am off my soap box, can you virtualize Exchange Server 2007? Yes, you can. It make perfect sense to me for development and testing environments. It makes perfect sense for a proof of concept, too. It even make perfect sense in small organizations that won’t push their Exchange implementation very hard.
Recently, I worked with a client that has a nice virtualization platform running Hyper-V RC1. They hosted mailbox servers, hub transport servers, and client access servers for their test environment. It ran wonderfully. They are considering doing it when Hyper-V RTMs because their expected load for 35 users isn’t very large.
UPDATED: Scott Schnoll posted the official stance in his blog post, Exchange Server 2007 and Hyper-V.