Actually the tethered crap pisses me off. Because most phones in the US are locked/carrier branded and crap, AT&T can easily load bloatware that restricts you left and right.
Tethering is a device-capable thing only. I tethered on my Sony Ericsson W810i. It was more like a modem then, but with my Nokia N82, and Milestone it was more of using it as a mobile hotspot. The point is these devices are fully capable. AT&T cannot in any way regulate what I do with my own device.
Sure they can claim to impose an AUP that states you can't do that unless you pay $20 or whatever the hell, but I feel for the iPhone users who open the tether screen and get bombarded with an AT&T warning saying that you can't use it unless you have it enabled in your account.
That's like charging SUV drivers a fee at the gas station because they guzzle gas. If you need more gas, you pay for it at the pump, not through an extra fee... but because your car uses more. Similarly, if you tether full desktop browsers probably eat more bandwidth. You'll pay for it through data usage. 2GB is 2GB. Tether or no tether, it doesn't make a difference to AT&T.
Of course they'll make us pay for something thats inherently a phone feature (like GPS).