It is said that a truly wise man never installs version one of anything. While Microsoft may try to muddy those waters by replacing version numbering with named products and service pack upgrades, this golden rule still applies. In the absence of a compelling reason to the contrary, we very much doubt anyone will be rolling out large numbers of Windows 64 bit desktop installations until at least Service Pack 1. Normally, we expect the first service packs for operating systems around a year after launch--which should, in this case, be the second quarter of 2006.
But looking at the Microsoft product calendar, 2006 already has a red ring around it. That's when Longhorn is due to appear, another 64-bit Windows operating system. Even if that hits at the end of the year, it's still within view of the putative Windows 64 bit SP1 date. Certainly close enough to justify a prudent delay in adopting the latter while we all wait to see how Longhorn itself pans out. And we won't know that for sure until Longhorn's own first service pack in late 2007.
This might seem an unduly leisurely approach, but in practice it may even turn out to be optimistic. 64-bit computing will only become important for clients once compatible hardware is widespread, and that won't be until the completion of the next big upgrade cycle in 2008. By then, the industry will have embarked on the whole tedious business of getting device drivers and utility software written and learning how the new 64-bit stuff can be made to work effectively.
There is always the chance that some killer application will appear that makes 64-bit clients seem much more appealing. We're not holding our breath: the stuff that holds us back lives at the other end of the network, where wider data paths and bigger memory spaces have a much more compelling tale to tell. That's a story for another day: on the client, though, 64 bit is a story for another year.
