Personally, I just switched over to Thunderbird, the e-mail client from Mozilla. A few months before I switched to Gimp, the picture editor. (That's Wilber, the Gimp mascot, reading the manual to the left.)
I had these programs on my drive for months before making the move. What I mean in this case is I started using these open source tools exclusively, and stopped using the closed source alternatives.
In fact, my main use of Internet Explorer these days is for writing this blog. About 90% of my time is spent with Firefox instead.
In all these cases, I decided that the open source programs were better, or that my old closed source programs were just not worth the trouble anymore.
But will people go through the same process with device software? Will they, for instance, all use Rockstar to run their iPods?
The reason is the continual support Apple gives the product. The regular updates are much like the daily updates your anti-viral gives you. They continually remind you of the product's value, and the vendor's care for you.
There is a lesson here for proprietary vendors, a lesson wise vendors have learned.