I'm not sure it's worth splashing out on a new passport (considering how expensive they are) when I've got no immediate plans to use one for its intended use. I never even used the one I have (apart from once as security at the Tate); I bought it for trip abroad with a mate that fell through. As for the Olympics tickets, I'll just go with the P@H option if I manage to get some, and it seems an expired passport is valid for such matters anyway.