Microsoft chose the recent IT Professional Forum in Barcelona to announce that the next version of Exchange and several other programs will no longer be developed to work as 32bit programs. Instead, you’ll need a server capable of processing in 64bit chunks if you want to run – and some of these are working names – Exchange 12,Windows Compute Cluster Server 2003,Windows Server Longhorn Small Business Server, Centro and Windows Server Longhorn R2.

In case you’ve forgotten, Compute Cluster Server 2003 is Microsoft’s stab at supercomputing, Longhorn is the next-generation server operating system and Centro is infrastructure software for medium-sized businesses. Some, but probably not all, of these applications will interest you. Unless you’re a confirmed Notes customer, Exchange 12 very likely will, however.

What Microsoft’s announcement means is that if you want to run the next Exchange, you will need a server based on Intel Xeon, AMD Opteron or similar chips with 64bit addressing extensions. If you’ve been spending on mail servers in the past couple of years you might already have made the move. If not, you might well be planning to make the move before Exchange 12 is scheduled to ship in late 2006 or early 2007. But Microsoft’s mistake here is to make the decision for customers rather than to be reactive and conservative. It’s interesting how little the media picked up on the announcement.

Conspiracy theorists might argue Microsoft buried the news – it merited just 83 words in a dense 1,400-word press release that also listed a series of other product announcements, including Dynamics GP 9.0. Like many of my peers I glanced over this and assumed Microsoft was giving 64 bits the thumbs-up but not giving 32bit the bum’s rush. So I missed the jaw-dropping bit where Microsoft, via server and tools boss Bob Muglia, assumes the role of nanny state: “The opportunity and value 64bit represents to customers is clear, and Microsoft recognises what is required to help customers make the shift,” Muglia said. “We are making big bets on 64bit technology and working closely with our industry partners to enable a smooth transition for customers.”

And “what is required” of course turns out to be a mandated server upgrade if you want the latest software.

To be fair, Microsoft posted a question-and-answer session in which Muglia responded to a query about the 64bit diktat. “When you buy a server today, it is going to be 64bit. The only real exception to that is if you are buying ... essentially a desktop machine run as a server,” is the gist of his argument.

Fine and dandy if you’re splashing the cash now but what about all those companies not buying new servers today? Exchange 12 is just a year away, according to Microsoft. So if you’re an Intel-only IT department buying Dell server boxes then by the time the new Exchange is here you will have had only two-and-a-half years refresh to fit around Microsoft’s plans.

Microsoft has made a miscalculation on server buying patterns here. Once that sinks in, a sizeable subset of customers aren’t going to like it making hardware decisions for them.