Sounds like they violated a couple of their own rules. Good thing we didn't need legislation to protect flyers rights....

http://www.delta.com/care/service_plan/index.jsp

9. We will provide full and timely information regarding the status of a flight if there is an extreme delay after you have boarded or after the plane has landed, and we will provide for your essential needs such as food, water, heat, air conditioning, and restroom facilities while onboard.

If an extended departure delay is expected prior to or occurs after pushback from the gate, we will:
Make timely announcements regarding the flight status on a consistent basis.
Allow customers to use cell phones and laptop computers and move freely about the cabin, in accordance with safety and federal guidelines.
Make every reasonable effort to ensure the aircraft is properly serviced and appropriately provisioned based on factors such as aircraft type, trip length and destination.
Monitor any customer situations surrounding passenger or employee safety or security which would require the flight crew to return the aircraft to the gate.
If the aircraft has landed and no gate is available, Delta will:
Make timely announcements regarding the flight status on a consistent basis.
Allow customers to use cell phones and laptop computers and move freely about the cabin, in accordance with safety and federal guidelines.
Notify Delta operational officials to accelerate a resolution after 60 minutes.
Apprise appropriate Delta senior management of the situation should it extend beyond two hours.
We are also working with airports to develop clear and consistent procedures to ensure safety and limit inconvenience during an emergency. This includes gate and ramp sharing with other airlines and making essential services available inside the airport.