>Eventually someone is going to iterate their software past Apple

Actually somebody already did. Microsoft gets a lot of flak for its design skills, but I think they did splendidly with WP7. Having used a Lumia 800 for a week I was extremely disappointed to go back to my iPhone 4S. I believe that the future of the smartphone market is a battle for supremacy between WP7 and Android, and I for one am rooting for WP7. Apple's last 'successful' iPhone might well be the next one they release, unless they have got something incredible cooking.