@ZackMorris,
I do not live in the US and may not fully appreciate the cultural nuancies, but does the fact that there is a waiting list indicate that the product has been a success? (Edit: thedead1440 has already touched upon that in, post #4.)

@ste-phan,
Agreed. I have been on PAYG for 15 years. Never had a subsidised phone in my life. The last phone I had before my current N900 was the Treo 600 and I had it for 8 years. It is still in perfect working order (and in many ways better than the N900), but it does not have a WiFi and GPS. And I replaced it with a phone that itself is 3 years old already.

The upshot is, I do not need a new phone every 18 months. I need a new phone when the old one breaks or a new one offers some fundamentally new useful feature. A new design or a new version of the OS is not a fundamentally new feature; addition of WiFi is.