My thesis is that CIO's are herd animals, making purchasing decisions based on the perceived direction of the herd. They sense this through Gartner research reports. There are many competitors, but Gartner is the name-brand.
If Gartner signals a shift in the herd, then alternatives may become interesting. How will Google signal this shift so that the herd can change direction? Does Google have the kind of name-brand recognition that CIO's recognize? Will they be the Izod of software the way Micro$oft is?
Note that we're talking about social pressure and name-brand. We're not talking about quality or functionality. We know that quality doesn't matter -- the evidence is the endless patch cycle for MS products. We know that functionality doesn't matter: corporate IT routinely removes, disables or replaces parts of Windows before configuring a standard PC image. Clearly, the Micro$oft solution wasn't precisely what anyone wanted.
Interestingly, if you ask someone, they'll tell you that MS desktop software "just works". As if Linux on the desktop doesn't work, or Mac OS isn't a desktop operating system. And after telling you that MS desktop software works, they'll tell you about the patch release cycle.
A great rationalization the Salvation argument: MS "standardized" or "integrated" desktop applications. I've been told that before MS, the desktop was a zoo of incompatible file formats and applications. I didn't recall that we had profound problems with Word Star and Visicalc. I think that this is justification for following the herd, not a real technical issue.
My favorite rationale is The Decision Is Already Made™: literally, "we're an all Micro$oft shop". This -- effectively -- forbids change or innovation. Since I prefer not to work with IIS/ASP/VB/C#, I always ask. And when I'm given one of the variations on The Decision Is Already Made, I know that we will have a number of strange problems arising from the exceptions to the rule. The presence of exceptions, however, is not permission to think outside the box.
How will Google break up the herd? If MS was our Salvation, why leave it now? If the Decision is Already Made, how will they get people to unmake the decision?