Microsoft’s (MSFT) April 8 end date for Windows XP support and technical fixes is here, carrying with it a built-in upgrade path for public- and private sector organizations and a significant opportunity for channel partners to guide businesses through transitioning to Windows 8.1 or something else.

For sure, Microsoft’s partners will continue to see XP-related business come their way.

Some 13 years after its debut in 2001, Windows XP still runs millions of computers worldwide, with its market share pegged at 27 percent, according to researcher Net Applications. Considering that there’s a very real—and well-chronicled—security risk to businesses and government organizations electing not to migrate upward from the venerable OS, it’s a bit baffling that Microsoft has yet to see an upgrade stampede.

One reason users are sticking to XP is that it’s a reliable, familiar, no frills OS, they’ve got software installed that’s compatible with it, and everything works. Combine that with the less-than-inviting reviews Windows 8.x has received, add in some hesitancy to act on the predicted security vulnerabilities of sticking with XP, and you have a dug-in installed base.

For the loyalist consumers and small businesses reluctant to upgrade, buying a new system with modern hardware and software already on board may be an answer. There still are Windows 7 machines out there in retail land to be found and, if enough users to go in that direction, it might spark a noticeable uptick in PC shipments. Some larger organizations may try to crank up a custom support agreement with Microsoft, despite the high cost. Or, it’s possible we might see a measurable move by some users to Google (GOOG) Chromebooks or Apple (AAPL) Macs.

On the security side, any networked XP system is going to be vulnerable from here on out. Users sticking to XP will have to take extra precautions, doubling or tripling up on anti-malware software and hoping it can help them dodge the expected hacker attacks. And, they’ll have to forgo IE browser upgrades because the newer editions don’t work with XP—perhaps even disconnecting from the Internet altogether, restricting the older systems to word processing or offline gaming.

What can channel partners do to move along an XP migration to Windows 8.1?

Because many businesses and organizations will blow right through today’s support deadline, Microsoft partners will be able to bank on a steady flow of XP-related business from the entrenched crowd, especially if news of the expected security intrusions gets louder over time.

Not only do the partner opportunities include offering XP migration services but also cloud transitioning services for customers willing to look at the bigger picture that moving off of the venerable OS brings.