Fibre to the premises.
I stopped using BT for telephone calls some time ago for all the reasons others have given above, poor service, couldn't-give-a-s**t-attitude, etc.
If I got five minutes alone with Ian Livingston and could give him one piece of advice before he starts his new job it's that if he wants to keep myself and many others using BT (either retail, wholesale or both) for broadband then he really needs to start making the right noises as regards fibre to the home and office.
Time was BT was the only affordable broadband option for those not in cabled areas or connected to a LLU exchange but now that the major mobile phone companies are offering broadband services with half decent speeds at competitive prices BT could really see their monopoly crumble.
I know everyone is by now sick of the whole "who will pay for upgrading the last mile from copper to fibre" argument, I know I am. We'll just have to see how that one plays itself out, but that's not what I'd discuss with Mr Livingston.
What I'd discuss is a new policy for fibre and a new approach altogether. What I'd suggest is that as soon as it's technically and financially possible that all new connections to an exchange be made using fibre optic cable rather than copper. I know it used to be the case that copper was cheaper that fibre but since that isn't the case any more then that particular argument is gone. Ok, I'm sure there would be costs at each exchange where this was done but BT are a big company that make big profits year on year. Put it this way, I'm sure it wouldn't bankrupt them. It would certainly cost a fraction of the amount that upgrading all the old copper to fibre would cost.
My other advice would be that BT finally admit publicly that copper has had it's day, even if some of us are going to be stuck with it for years to come, just say what every tech savvy BT customer has known for years: fibre to the premises is far, far superior to copper. Then I might actually have some respect for the guy. I might even consider remaining a BT customer.