You can never provide too much information. If they really don't know, then I think updates every 45 minutes or so is appropriate. Most customers would be forgiving and would actually appreciate the updates if the airline is open an honest with them. Also, don't change the story! If it's a mechanical problem, don't say later on that it's due to weather.
Also, don't blame the employees at the gate for feeding you the BS! They are only telling you what they are being told. They are simply the messenger, the message is most likely coming from much higher up! However, I personally love it when an airline employee refuses to not give customers a line of BS.
For example, on our most recent flight to MCO we hit weather problems in Orlando and could not land. The pilot could have easily said "we are circling MCO and are in-line to land", but he didn't, he instead got on the intercom and said "Well folks, we are being rerouted all over the state and will land whenever air traffic tells us to." Did his being honest with the passengers make the delay any shorter, no, but it helped make everyone more comfortable about the whole situation because the pilot was being honest and provided some light-hearted comic relief. It always seems like pilots are pretty honest compared to other employees. Now is that all a front? I don't know, but it does make me trust the pilot.