I am not sure if the EU rules mandate that, but I don't think the US government does. Here is an overview of pax rights from the DOT, and it pretty much says that you are at the airline's mercy.

I was on a NW flight a couple of years ago that was scheduled at 8:00 pm, after 3 hours of delays, they could not come up with a crew (in MSP), and postponed the flight until 8:00 am. The only thing they were offering was a phone number for distressed traveler rate hotel rooms. They might have done more for elites, but certainly not for the majority of the pax. Not so much as a free round of drinks when the flight finally left 12 hours late.