We help companies upgrade systems on a regular basis. I know that it is not as easy as it sounds.When RBTT ATMs were spewing money many moons ago, it is alleged that the cause was a system change/upgrade gone awry. Rushed changes can be as bad as, or worse than whatever it is they're trying to fix.
Big companies such as CNN got hit by this worm. I saw them struggling with the worm live on television.
I guess companies will re-arrange their priorities to put patch management as a critical item. Let us see how many of them apply patches without testing them adequately now.