I have to agree with a lot of the comments that Chrysalis makes as a mildly experienced user, and as someone who can appreciate the different aspects making up a 'broadband' service. I also agree that to offer customisable plans would be great too (just wondering if they would be technologically or commercially viable.)
However, I think that a lot of services (especially ntl) are aimed at the lowest common denominator, ie Joe Public. Thats why we get different, affordable, lower speed tiers, access to e-mail and news servers, and dare I say (controversially) a cap intended to provide a fair service for all.
As long as everyone else (AOL, Wanadoo etc) keep offering these same services, ntl would be making a mistake by cutting them.
There, a hastily written and ill thought out comment, with some giant holes, but I have to go to work now....on a bank holiday