Wireless carriers are considering charging customers per service: they want to charge for Facebook use, YouTube, Skype etc.
http://www.engadget.com/2010/12/19/wireless-carriers-openly-considering-charging-per-service/
I wonder how that would fare in an anti-trust suit.
If they want to model it on phone service, I think they would be okay: charge per minute, free within network. It's agnostic to what you're doing except for a simple binary: you're staying within our network or you want to connect out beyond it.
The equivalent would be a charge per megabyte, no charge on sites within network (whatever that would mean).
Where the anti-trust thing becomes an issue is that I don't see how any one carrier can start doing it alone. Anyone who really wants a data plan will jump to another carrier and people who don't want it will cancel the plan. So that means coordinating, which means a form of price fixing, which means feds jumping down your throat.
I see this as more of a positioning thing. Throw out the worst case scenarios, get people outraged, and then back off to something that looks a lot better, but would have outraged people if thrown out as a first offer. By moving the awful line, it creates a different perspective.