I see articles like this one--explaining the migration of one's mom, grandma, etc. to Linux--and I can't help but believe it's proof positive that the migration in question never should have happened. If it requires an article explaining the success (or failure) of the migration, it's too difficult to bother doing.
At least this author was honest:
So, is Ubuntu Linux ready for this type of installation? Yes, provided they have someone with some Linux expertise at hand to help them.
I'm an open-source believer, but that belief does not mean that I believe open source should be used where it is a less viable solution. At some point the desktop Linux crowd is going to realize that its goals (control, primarily) don't necessarily mesh well with those of the average user (usability, primarily). This is fine. It's not cause for alarm.
I've had my entire extended family move to the Mac. (With eight kids, this is no small feat.) I didn't have to go over to my siblings' homes to install it for them and work through the kinks. It just worked. No technical proficiency was required.
Which is the point of desktop computing in the first place. It's supposed to lower the bar to getting things done, not raise the bar for the sake of ideology.
There are exceptional open-source programs for the desktop that run just fine on the Mac or on Windows: Adium (chat), Neo/OpenOffice, Firefox, Handbrake, etc. This is the best way to introduce open source to one's grandma, not by pushing a new operating system paradigm to her.