Last week, an ntl cust serv rep told me over the phone, in between saying "DUHHH" a lot, that my area (NW Surrey, TW20) is projected to go live for the TV-Drive HD service on Jan 23rd. This tallies with some of the other posts I think.
I then asked him if it used the intended mpeg4 standard, or had that been abdandoned in favour of the cheaper/easier mpeg2 like I've heard - it sounded like his head then imploded, so I never found out.