I also figure once all the available stories are out on DVD they will go and blue ray them. *shudder*
The problem with that is translating 1970s-era videotape to high definition, along with film inserts for which the original elements no longer exist, doesn't work at present. If you want to see how it looks when they try, there are Confidential episodes on the Blu-ray of the new series that include clips from classic-era episodes, and the images suck. (If you have the Series 5 set, one of the Confidentials relating to the Silurian 2-parter if I recall has clips from either The Silurians or The Sea Devils, I forget which.)
One of the (many) reasons why DVD has survived rather than going the way of vinyl is that Blu-ray and high-def are not friendly formats for a lot of older TV shows. Anything shot on videotape, or on lower-grade film, can't - under current practices - be transferred to Blu-ray in an acceptable manner. Now I happen to be of the opinion that they'll figure out a workaround someday, though it may be a "reverse-VidFIRE" process where the videos are all transferred to film or something. But right now that's the main reason why a lot of older series aren't (and won't likely be) on Blu-ray. If a show was shot entirely on film, that's a different case (I'm assuming a Blu-ray release of, say, the Emma Peel era of The Avengers is not far off; ditto Secret Agent/Danger Man and The Saint and the Gerry Anderson shows, but we're not likely to ever see the shot-on-video-then-kinescoped Honor Blackman era of The Avengers on BD).
Right now, the only classic series story that could be put out on Blu-ray is Spearhead from Space because it was shot entirely on film. So could the 1996 TV movie. Everything else is either all-video or kinescoped (1963-1969), a hybrid of video and film (1970-1985) or shot completely on video (1986-1989 and occasional Tom Baker stories). I am assuming that when Pyramids of Mars was included as a bonus with the DVD and Blu-ray UK release of Sarah Jane Adventures Series 4 that it was just a straight DVD and not upconverted.
I was hoping that when the original 1960s Twilight Zone was released to Blu-ray last year that its half-dozen shot-on-video episodes would indicate the "video barrier" had been broken for BD. But I'm told they didn't turn out very well.
So when it comes to Classic Who and most of the other old TV shows I enjoy watching, especially classic sitcoms like All in the Family, I expect to have to stick with not only DVD, but also Plasma TV, as my brother and I did some extensive research before I took the HDTV plunge, and plasma in my opinion is the only TV format that renders lower-res images (broadcast, DVD, even VHS) in an acceptable manner. LED and LCD are fantastic for Blu-ray and HD broadcasts; but if you like watching anything else, prepare to be disappointed (friend of mine made the mistake and said she was very disappointed she couldn't watch her favorite shows anymore because they looked terrible; I recommended she swap out for a plasma).
Alex