My theory is that companies that get big tend to get stupid - it happened to IBM back in the 80's, it's happening the Microsoft now. Consider their "Windows 7" plans - here's what should have happened, based on an SDTimes story:

In October, Microsoft distinguished engineer Eric Traut discussed “MinWin,” a project to address Windows’ dependence on legacy DLLs and libraries when executing older applications, during a talk at the University of Illinois at Urbana-Champaign. At the time, Traut said that MinWin, a stripped-down version of the Windows kernel with other core components, would be the foundation of Windows 7 and other releases of Windows going forward.

But, that was way, way too risky sounding for the risk averse management that tends to take over at big firms. No - we get this instead:

However, after months of anticipating big changes for Windows, Steven Sinofsky, senior vice president of the Windows and Windows Live Engineering Group at Microsoft, said that MinWin would not be a part of Windows 7 after all, in a Q&A with News.com published yesterday.

Which pretty much defines the "old, big, and stupid" thing that pervades big companies. The only real change at MS will start happening when it's forced on them by external events. Until then, they'll lumber along dumbly.