Nice to see how a large organization handles these kinds of reports, but this part really bothered me:
...one day unexpectedly Word started crashing for people. We hadn’t changed anything. It turned out a new version of a popular add-in released and the crash was happening in the add-in, but of course end-users only saw Word crashing.
Yeah, stupid users. They only saw Word crashing... but wait, Word was crashing. Sounds like there's a bug in the plugin system - just as applications shouldn't crash the OS, plugins shouldn't crash an application.
Hell, GMail warns me about slowdowns when I load it with Firebug is enabled - taking responsibility and acting on a brower add-on which is affecting a web app's user experience seems the wiser way of dealing with issues than blaming the user.
Summary of last part:
Please don't hate us, interwebs. You messed up Vista's PR glory, please don't mess up Windows 7. Did we mention it might be a hardware problem?