My September 24 column was all about running Microsoft Exchange Server 2007 on Windows Server 2008 R2. Quick summary: Microsoft said "we won't support it," and I spent a whole column explaining why that seemed like a sensible idea. (See "Exchange 2007 and Windows Server 2008 R2.")

Last week, Microsoft made that column obsolete with a new announcement: They are going to support Exchange 2007 on Server 2008 R2 after all. The announcement, by Kevin Allison, the general manager of the Exchange Customer Experience team, was pretty vague, promising that "in the coming calendar year we will issue an update for Exchange 2007 enabling full support of Windows Server 2008 R2." That leaves a number of questions open, such as exactly what form this update will take (Service Pack 3? A really large update rollup?) and when it will ship.

I still think the reasoning in my previous article is sound. First, Microsoft hasn't been supporting upgrades to the OS of an Exchange server after Exchange is installed on it, and it seems unlikely that they'll suddenly start. That situation means that the utility of Server 2008 R2 support will initially be limited to those customers who are willing to do clean installs of R2, followed by reinstallation of Exchange on the upgraded machines. If you have to do installs of both the OS and Exchange, you might as well move straight to Exchange 2010 (except that you might, depending on your licensing plan, have to buy Exchange 2010 separately).

Second, the list of reasons to upgrade to Server 2008 R2 still doesn't strike me as super-compelling for Exchange. There are definitely some good reasons to upgrade domain controllers and global catalogs, remote access servers, and other roles, but the benefit for Exchange is smaller.

So, if I'm right (and even if I'm not), why did Microsoft reverse its stance? Simple: Customers demanded it—loudly. This reversal is a great example of how customer feedback, communicated through a variety of channels—including Microsoft's field sales and technical support force, but also through blogs, forums, and other Internet-based feedback mechanisms—can cause even a very large company such as Microsoft to change its stance on something. I take it as a positive sign that the Exchange team is listening to us and taking our requirements into account, and I hope that this trend continues.