An article on the register today indicates that vm are going to put the 50meg service out at a premium
The firm announced strong underlying profits today and said it expects its forthcoming 50Mbit/s network upgrade to further distinguish it as a premium/expensive ISP.
http://www.theregister.co.uk/2008/08/07/virgin_q2_2007/
No real surprise there but not sure they want to be establishing a mind set of being an "expensive" provider.