> AT&T can raise their data rates for everybody and attrit customers to other providers (or to less lucrative featurephone packages). Or, they can find ways to charge higher rates to less price-sensitive customers.

Sprint seems to have taken a middle approach. They just charge all of their smartphone customers a 'premium data charge' of $10/month. This is a lot less than a traditional 'tethering plan' would cost, and my smartphone came bundled with the Sprint Hotspot app, so I can tether if I want to.

This seems fair to me (even in nerd-arbitrary logic), since the gap between computer and smartphone is so narrow, and the gap between smartphone and dumbphone is so wide.