As Brian Cox's Wonders of the Solar System ended last night (25 March), BBC HD finished its five-plus years' run as part of the British TV channel line-up. In its place, having started at 6am this morning, is BBC Two HD, a simulcast station that apes the schedule of the regular BBC Two, broadcasting shows in high definition recorded natively in that format and upscaled versions of everything else.
One of the benefits to the new BBC Two HD is that it will run nigh-on as a 24-hour channel (bar brief gaps in the middle of the night). The BBC HD channel only went on air at 4pm each day, being the best of the BBC's HD content not broadcast on the existing BBC One HD.
Shows to look forward to on BBC Two HD include The Great British Bake Off, QI, Later... with Jools Holland, Top Gear, and, er, a stack of other shows that were also run on BBC HD. Nonetheless, it'll be good that they'll be broadcast in the same time slot. Occasionally, shows were shown out of sync with their standard-definition counterparts.
BBC Two HD can be found in the same place on electronic programme guides as BBC HD was, in a like-for-like swap.