Whether you prefer the cancel and re-book option or to wait around in the hope that the delay won't be too long really depends on why you're travelling and what deadlines you have to meet.
As others on this thread have said, the crucial thing is information. If you can tell us what's happening as soon as you know, and give us an honest estimate of the delay, then we're going to be a whole lot happier. The worst thing is when I feel I'm being fobbed off, or that the person giving me the information doesn't actually know what's going on, but is trying to pretend that they do. If you don't know what the hell's going on, then TELL us! We can accept that more easily than the feeling that we're not getting the whole story.
On the other point, while I agree that being asked to turn up at the gate only to queue for ages to board is irritating, I can't BELIEVE the number of people who turn up late and then get on the plane looking like they think it's funny. How arrogant/selfish do you have to be to keep, say, 300 people waiting and maybe miss a take off slot because you wanted to spend a bit longer in the bar??