The good about Windows

There is one good thing you can say about Windows: It's a known quantity. I couldn't run FireFox 3 Beta on my Linux machine because the moludy old version of RHEL 4 my company lets me run doesn't ship with the right library set. Furthermore, it's so old that the right library set won't compile without more handholding than I care to apply. With Windows, the target is well understood, even if it is an older version.

Service providers can learn from this. Make sure that your outputs withstand the test of time, and build into your deliverables an upgrade path that cannot become obsolete. There will be time for EOL for your outputs, but make sure you take care of the customers that you leave behind. At least leave a kind word and some suggestions for dealing with life beyond support.