Yes they are the 2 pins type and the sort that go over your head as opposed to in your ears.
We normally take our own though as we bought the 2 pins adaptors from Maplins (at least I tihnk that's where we got them from)
They are normal 3.5mm single plugs, and they are rubbish ! Take your own if you have them and want to actually understand what is being said in the movies !
Definitely. We got a cheap pair in Florida Mall a couple of years ago and I certainly notice the difference when I take them off. When we flew out to Chicago a couple of weeks ago with BA they actually handed out free noise cancelling headphones.