This happens all the time in Alaska. It's usually because there are not enough passengers on the flight.

I've had the 10:30 flight from Barrow to Anchorage cancelled due to "mechanical difficulties." They just rebooked me on the 7pm! That's 8 1/2 hours. I asked if it was just delayed since it was mechanical and they said "No. Cancelled." Of course this was at about 9:30. They already knew they couldn't get the plane fixed.

I usually just go with it up here but that bugged me because it was a Saturday. I had been gone for awhile and had to be at work on Monday. The flight arrived around 10pm so I basically had Sunday for my weekend (which included doing all the laundry from the trip!).

I'd say it sucks but 1 1/2 hours isn't that long. Maybe I'm just used to it. I usually plan on about an hour delay of some sort.