Windows 7's Oct. 22 release will be an exciting day in Redmond, but IT folks should mark it for another reason. It's the beginning of XP's end.

Don't get me wrong, I'm not a raving XP fan. But Vista's flop gave us a long run with a relatively stable platform that actually got better over time. You can buy a new machine today with a clean XP SP3 image and have the same look and feel you had when XP came out in 2001.

A lot of companies are doing just that, with 70% of corporate desktops still running XP, Forrester finds.

Full Vista rollouts are rare, and instead most tend to have what Roy Atkinson, director of end-user support at the Jackson Laboratory, calls "Vista leak-out." Less than 5% of Jackson's several thousand desktops run Vista; most are on XP. "We only deployed Vista if there was a driver or application that clearly worked better," he says.

It would be nice to have the tighter security, 64-bit OS, and higher performance networking of Vista. But delays, bugs, hardware requirements, and bad market perception have held it back.

There's no need to jump off XP yet, but it's going to get harder to stick with it, especially later next year. Mainstream support for XP ended April 14. This means Microsoft doesn't have to release any new features or make any design changes. Security fixes will be released as needed, but non-security hot fixes won't be released to the public.

Phone support is available if you're willing to pay and if you bought extended support from Microsoft (that deadline was July 14).

"So what? I don't call them anyway," a particularly anti-Microsoft IT director says. He should read the support terms closely, because there's more here than the end of free phone support. This is Microsoft's official way of saying it can leave XP alone if it wants, ending all feature updates and enhancements.

XP could start to get shortchanged on feature development as soon as Oct. 22, when Windows 7 and Windows Server 2008 R2 are released. The new Windows Server 2008 R2 features--including DirectAccess, which provides simplified remote access; BranchCache, an automated file-caching option for remote offices; and an updated offline folder synchronization capability--will only work with Windows 7 clients. No XP or Vista updates are planned.

If Microsoft adds any features for XP, it would have to add them for Vista, too, and Microsoft is moving as fast as it can away from Vista. Windows 7's October ship date is three months earlier than the company's targeted January 2010 release date. Businesses can get it Sept. 1. Microsoft early? I have the same stunned reaction as when my 6-year-old cleans his room, and I find myself asking, "What's he hiding?"

Other Influencers
HP, Dell, Lenovo, and all the other PC makers will continue to support XP; their laptops and desktops all offer supporting drivers. But manufacturers will now have to support three Microsoft operating systems -- 7, XP, and Vista -- each requiring a slightly different development and testing program. These companies work on tight margins, so the chance to cut that cost by a third is going to be quite appealing as time goes on.

What would get people like Atkinson to move off XP sooner? "If manufacturers were to stop making drivers or showed a Windows 7 driver that dramatically improved performance," he says.

It's fairly easy for vendors of major applications -- accounting, operations, etc. -- to keep providing XP support. The problem for XP is going to be support system software, especially antivirus and anti-malware products. Most have already announced Windows 7 support, though only for their latest versions. They're going to want to migrate upward in order to focus on the common core OS that's part of Vista and Windows 7. You can also expect vendors that want you on Windows 7 to start touting the ability to run "XP Mode," which is a Windows XP virtual instance (or an instance of an XP-compatible app) on a Windows 7 machine.

One other question is what version will run on netbooks, which have quietly slipped into IT and engineering hands all over the place. The great thing about these little machines is they can run XP Pro, and they fit right in with all your desktop management tools.

But the future OS for the corporate netbook is fuzzy at best. Windows 7 lower-end editions are aimed at the netbook, but they don't have domain login or group policy features needed for a corporate setting. The final Windows 7 release will show how beefier versions run on a netbook; if they can't authenticate against the domain, they'll be of limited use in any company. If it doesn't fill the authentication gap, you can expect multiple vendors will step in.

Do The Math
Assuming you've purchased some new gear this year, and you'll be keeping it for four or five years, you're looking at a replacement cycle in 2013 or 2014. That means you'll have to deal with the new version of Office announced last week (see story, "Office 2010 Available For Private Clouds" ) and four to six core server upgrades. Don't forget, Microsoft isn't required to release any enhancements or bug fixes to make XP work with these newer products.

3 Steps To Take

Time To Get Moving On Win7

Download the release candidate
Get your team looking at it. Windows 7 is built on the same core as Vista; you'll want to double-check any problems you had on Vista with the new OS. Vet your software vendors
Make sure they're well on the way with testing and certification. Historically, app vendors lag 6 to 12 months behind in support--make sure it's not more. Have a plan
Start laying out your pilot and rollout plans. You can assume Microsoft will push hard to have a service pack released by next summer. That brings you into fall 2010 to start major rollouts.

So that's it, it's time to get a Windows 7 strategy in place. At a minimum, you should have someone download the Windows 7 release candidate and start checking it out. You'll want to know if your key vendors are getting their apps tested and certified for Windows 7, and get a plan in place for a pilot and rollout.

As for alternatives to Windows 7, don't count on Google's Chrome OS. It won't be ready for secure, compliant computing for a while. If you're set on a Linux kernel, Novell's way ahead, but you'll need a Novell-centric directory structure for true management and control.

Macs still lack an enterprise set of tools that work seamlessly without requiring Mac servers. Plus, your Apple deployment would have to include Microsoft Office for the Mac, which doesn't include Outlook.

In reality, if you want a robust OS that's focused on giving users a ton of options, has plenty of hardware and software vendors fighting for your business, and has the third-party tools and support to give you the control over access, security, and data, it's Microsoft.

But will it be XP or 7? It remains to be seen whether the need to obtain ongoing support will end up forcing companies to move off XP, or whether they'll be able to make this decision more rationally, based on their budgets, the software's features, and the potential ROI.