Churn, like it or not, is always going to happen to greater or lesser degrees. What you are saying is of course correct: that with a higher volume of lesser engaged users, churn is going to be greater.

The challenge IMO is what can be done to engage that volume and help produce 'ideal citizens' out of it if you will.

I don't have the whole part of the answer there, but I think that outreach activities like the Maemo Greeters program was certainly a step in the right direction and I think more activities like that are a great idea. Users communities per country with, say, 6 month meetups aren't even that unfeasible with the volume that devices must be selling in now - imagine what that is going to be doing to the more gadget-enthusiast amongst them...