I've just conducted my own mini-poll.
I just called a dozen or so friends and family who are running one iteration or another of the cut-down version of Slackware 12.2 that I originally built for my Mom (all I could get hold of in the thirty minutes I allowed myself for this exercise).
Universally, they didn't realize that they were calling me for support at least an order of magnitude less than they had been when running WinXP.
So to answer the question, it would seem that end-users don't even THINK about support, unless the thing is broken, and then they want it fixed ASAP.
Side note, comment from my Dad: "So that's why we never see you anymore ... Maybe we should put XP back on your Mother's machine" ... Must remember to make time to visit the parental units more often ...