Broadband TV News is reporting that BT have launched BT Vision to the general public. The V Box will cost £199, plus a £60 installation charge and a £30 connection fee (so, really it's almost £300). They will be launching a self install package at some point in the future. The BT Vision web site doesn't mention any of this yet. According to the article, the V Box will first be available from John Lewis stores, and then eventually at Comet.
I think £300 is a bit steep for a PVR. It might not have been too bad if the V Box had some Media Centre features (ie, I could use it to view content on the PC, and the ability to transfer files between a PC and the V Box). But from what I can tell, it doesn't - though for all I know it might, as the BT Vision website is a little thin on technical detail.