As reported here by the BBC: http://www.bbc.co.uk/news/technology-10760069
I pay for the 8Mb service from BT, but my download speed is usually about 800kb, so only about 10 per cent of what's being advertised (I understand there's all sorts of things which slow it down, like distance from the exchange and your home's internal wiring).
I suppose I should be apalled, but I think 800kb is still pretty quick. I can download an album in about 1-2 minutes, and a 40 minute episode of a TV show off iTunes in about 8-12 minutes. How fast do most people need it to be?