I can today confirm that Torchwood will be heading onto HD-DVD and Blu Ray disks sometime early 2008. The series, which was filmed and broadcast in High Definition, was initially touted for a HD release, but this failed to materialise because 2 Entertain (the home entertainment arm of the BBC) couldn't decide which format - HD-DVD or Blu Ray - to support.
Now, following the likes of Planet Earth and Robin Hood the series will be released on both formats, as a a complete series one package (presumably around January or February time to tie in with the launch of series two on BBC Two). I have no information on whether Warner will release the HD boxsets over in the USA, or elsewhere around the world.
The boxset will have the same content as the standard definition edition, which goes on sale November 19th with an RRP of £54.99. No price tag has been attached to the HD edition. More news on this as and when it comes in.