While Sun Solaris UNIX isn't in any danger, Linux definitely could someday replace Windows.
From the article:
The common arguments for switching to Linux are replayed over and over, rarely taking into account some very important benefits that the Unixes have to offer. With Sun's latest developments, and some not-so-new but overlooked features, its find it difficult to believe Linux can ever take over all of Unix's traditional roles.
Frequently, people to use the fact that Linux is "everywhere" to argue that sys admins are easier to find, and therefore easier on the personnel budget.
Do you agree?