I agree with Entwood and Den. AV Would result in coalition govt at every election, with minor parties holding the balance of power. The tail would be wagging the dog. We would lose forever, the possibility of having a strong govt. with a healthy majority who take the country in a certain direction, and if we dont agree with that direction we get the chance to kick them out and replace them with something entirely different after 5 years. I know this system has been badly corrupted in recent times, but there is still a chance it can be put right. With AV that chance would be gone forever.
I say this as a someone who votes for a minority party. My own self/ short term interest would say vote AV, but I thinks its wrong, and would be very bad for the country in the long term.
Im wondering what odds I could get at the bookies, as I reckon it aint going to happen. The English dont like big sudden changes.
The only chance it has of getting voted in, is if there is enormous apathy, and the Notting Hill Luvvy types who support it mobilise themselves in a big way.