I'm coming in here arguably late, so this might be a repeat. I have to wonder if Mr. Stephenson actually believes Apple would have made that deal w/ ATT, esp. when, even when the iPhone was announced EDGE/2G was "old hat."
Purely, anecdotal, but back in '07 I was a happy (one of the few) Palm on Sprint user. I was really on the fence when the iPhone came out b/c I really didn't want to go to ATT, and, honestly, I was skeptical of the iPhone's touch keyboard. If ATT had not offered unlimited data like Sprint and VZW did at the time there would have been no way I would have switched.
And, to that point, me being grandfathered with unlimited data now keeps me tethered to ATT. Maybe when Sprint goes LTE I'll have to reconsider, just to relieve Mr. Stephenson of my apparent burden -- even though I, like most, don't use more than 3GB/mo of data.
Quick add: And shorter Mr. Stephenson on iMessage hitting into SMS/MMS revenue: We are mentally stuck in 2003 and out of new ideas.