* Wouldn't this fall foul of anti-cartel laws, could all the ISPs get together and decide to limit what they sell without the government objecting?
* What's to stop someone starting their own ISP and not restricting access, could the network providers refuse to sell bandwidth to them?
* They're limiting supply to something artificially in order to boost the price. Unless I'm mistaken and it somehow costs less to only serve Facebook and MSN, there's big incentive for one of the ISPs to break ranks and offer unlimited access without it costing extra.
* What about mash-ups? My Google desktop wouldn't work if all the other sites that serve content to it were blocked. How would they explain that to their customers?
What do others think? Is this realistic threat?