Recently, I wrote a story about the vulnerabilities of Web applications in which Alan Paller, director of research at the SANS Institute, predicted, "Security will drive people to centralized applications."

That's in fact what I'm hearing from some of the attendees at the 2006 InformationWeek Fall Conference. The difficulty and expense of keeping desktop and laptop PCs secure, not to mention provisioned with licensed software, is making some IT execs re-evaluate the need for full-blown PCs.In a conference session I moderated with Equifax CTO Robert Webb, Webb validated the notion. (At Equifax, they've banned wireless networks completely to avoid potential security risks.) Others I've spoken with said as much: PCs are a liability. Add to that dissatisfaction with the price of enterprise software licenses and the not-inconsiderable hardware requirements for Windows Vista, and you have the potential for a large-scale defection from the desktop model in the years to come.

What's more, the need for mobility is also likely to make centralized applications, or at least centralized data, even more appealing.

While thin clients may be an attractive option for certain types of businesses, such as call centers, the desktop (and notebook) PC won't disappear. Local processing power and local storage remain necessary for many use cases. But IT admins are likely to look at those use cases more carefully going forward and weigh whether full-blown computers are necessary for everyone.

At lunch today, one IT exec talked about how some companies are exploring variations on the thin-client model involving local caching of data on PCs that then gets withdrawn to a central store once the worker logs out. The goal, as he described it, is to enable mobility and to enhance security without forcing workers to endure the limitations of dumb terminals.

If these random conversations reflect broader concerns among enterprise IT pros, Microsoft has one more reason to worry (beyond the general threat posed to its business model by ad-supported software services and open-source software). That's why I believe Microsoft will acquire Citrix within a year.