I have been looking for the 'Lost in Time' Boxset for ages. I think it's confined to eBay etc. these days (at least here in Australia that is). I think those two stories (The Tenth Planet and The Ice Warriors) depended heavily on the success/popularity/viability of the animation which was achieved for the release of The Invasion. I am unsure how the DVD audience responded to The Invasion (personally I thought it was decent enough) and whether or not 2|entertain had intended or still do intend to release those particular stories. If RTD was still the Show Runner then I would have said that would be a probability, but now that Mr Moffat is on board I think he will move on and only worry about his own characters.