Like many large companies living off past glories, MS is starting to lose track of their customer base - consider Walter Mossberg's observations about his new Vista machine:
I also was shocked at how long this machine took to restart and to do a cold start after being completely shut down. Restarting took over three minutes, and a cold start took more than two minutes. That suggests the computer is loading a bunch of stuff I neither know about nor want. By contrast, a brand new Apple MacBook laptop, under the same test conditions, restarted in 34 seconds and did a cold start in 29 seconds.
Over time, this has always happened to a Windows machine - but now it seems that MS is allowing the "bit rot" to set in before you even get the machine. My Mac Mini, a 2 year old G4, boots almost instantly. The XP notebook I'm working on right now? It takes minutes to shut down, never mind restart - and even once the desktop shows up, there are scads of things firing off in the background.
I suspect that MS is closer than anyone thinks to the same brick wall that IBM slammed into back in the early 90's. It won't kill MS, anymore than the wall killed IBM - but it's going to hurt a lot, and cost them a lot of influence.
Update: Scoble notes that this is an unintended side effect of the various governmental attempts to "help" consumers with the MS "monopoly".