many of the stories I've seen have said AT&T is just all pissy because they won't get their $20 fee to tether it to the blackberry.

Supposedly, AT&T is able to see if customers are tethering to smart phones and has started asking them to pay the fee. The bridge app on the blackberry supposedly makes both devices appear as one, so AT&T can't tell if it's one device or not, and can't charge.

It's just a matter of if the service provider is taking the same stance AT&T did by blocking the app.