Yes. Why shouldn't they?
because the internet is public property and is a common medium - they're just licensed to host it by the US Gov as part of their common carrier status
If they want to make bad business decisions and replace their services with crappy ones then they'll lose their customers to those ISPs that don't.
no they wouldn't - because that is impossible to do - all those "local ISPs" buy their bandwidth from the Big Comm companies and are subject to every anti-consumer thing they do.
Short of a huge organized cartel of ISPs (which would be illegal) I can't see how at least one "neutral" provider would not appear.
they're ALREADY a huge cartel - the communications industry, the oil industry, the pharma industry, RIAA, MPAA, etc are all cartels
And any sort of regulation is almost totally unenforcable as far as I can see.
then you have sun glasses on in a dark room - it's REALLY easy to tell if a server/router is traffic shaping
For example, if a user or group of users can't download tracks from iTunes at their full capacity, is that because of discrimination or a multitude of transient or permanent cross-network issues? Is the ISP overloaded? Is iTunes overloaded? Are any of the intermediate nodes experiencing troubles? Has a low-speed router link been selected over a malfunctioning high-speed one?
those are all testable conditions