With new superior models coming every year, time for Apple to do some innovation in the business-model (well, in addition to the app-ecosystem they created) and move to a subscription-based model :)
One pays few grands (say $2k) every year to upgrade i/pod/phone/pad to the latest version.
(well, they have recycling program with 90% depreciation!!)
As it turned out, this made an enormous amount of people unhappy. I think they abandoned it.
Apple does have an annual subscription service, MobileMe (or whatever they are calling it this week). As far as I can tell it has had a very low rate of adoption, despite coming free (for a limited time) with new Macs. Heck, I have a hard enough time convincing random (Mac using) strangers to buy a damn external drive and turn on Time Machine. Don't underestimate user inertia.
The only problem is that there's way to much risk to do this unless you are Apple or have a direct relationship with Apple. Then again, maybe the float would cover the risk.