Exchange 12 to be 64-bit only

Breaking news: Exchange 12 will be 64-bit only. I have a lot more detail to post on this, but they’re about to close the forward boarding door– more when I land in Cincinnati in an hour or so. Here’s a link to the umbrella press release from IT Forum.
Why the change? x64 technology is already widely deployed, and using it with Exchange reduces the I/O count dramatically– by up to a factor of 4. This is huge, since IOPS are much more expensive than RAM or CPU. (If you don’t believe me, try pricing 16GB of DRAM and a dual Opteron server compared to an EMC SAN and get back to me).
One objection I anticipate hearing is that this will strand customers who aren’t on x64 hardware. I’m resistant to this argument, though, because even low-end servers now often include x64-capable CPUs, and this trend is only going to accelerate between now and the time Exchange 12 ships next year. Organizations that are planning to move to Exchange 12 after it ships can easily buy x64 hardware any time between now and the time they upgrade, usually without any increase in cost. Of course, I expect to hear criticism of this move because some customers won’t be prepared to move to x64, but the fact is that there will always be customers– for any product– who don’t want to, or cannot, upgrade when the manufacturer wants them to. Sure, there will be Exchange customers who will cling to their existing versions, but that has always been (and will always be) true for Exchange, Notes, Workplace, OCS, SAP, and any other software in this class.
The big news here, to me, is that Exchange is once again breaking ground in delivering a new technology– and in this case, it’s one that has the potential to radically alter the scalability and cost factors we’re used to working with. I can’t wait to get my hands on some E12 bits and start testing!