RE: Copper? *cough*
Hi Steve - I'm not sure what you are referring to - ADSL in the UK is not provided on lines where the last mile is delivered using aluminium.
For a few years therefore, those with lines delivered using aluminium could not get broadband. Later however, BT devised a process whereby those people, when ordering broadband, would be provided with brand new copper lines.
The areas where aluminium provided cannot be described as 'large chunks' - that is over-egging it - those in this position are very much a small minority. I am sure if you look you will find figures for this...
Very early on (we talking a number of years ago), some broadband may have be provisioned on aluminium before BT realised this was a bad thing I suppose.
If you yourself are unlucky enough to have an aluminium line with broadband on it, i suggest you contact a good ISP and ask them to provide you with broadband on copper. A provider who is smaller and a bit more technical than most like Zen, Entanet, Andrews & Arnold are more likely to understand this issue than some of the larger consumer ones like BT, Orange, Carphone etc.