I'm looking at other options, like segmenting Windows XP systems on their own isolated network. I'm even thinking of going as far as preventing them from reaching the Internet. Of course, that will render them essentially useless. But the Internet is where the threats are, and without adequate defenses, it's only a matter time before those systems get compromised.
Another option is application whitelisting. That's a really cool technology that I've been looking at for some time now. But it's just not realistic for me to roll that out before the deadline. There's simply not enough time. Application whitelisting software is a good way to prevent malicious code from running on an endpoint, but it could take weeks or months to set up on each system. We don't have weeks or months. In any case, we have dropped everything else and are running full speed ahead with upgrading my company's computers. How long will it be before we have to repeat the same drill for the next-generation Windows platform?