It seems weird to me that we haven't heard more about them. FWIW Amazon has "The Tenth Planet", "The Ice Warriors"(39) and "Moonbase"(33) and others listed for pre-order, but no release date yet. Amazon UK has "Doctor Who: Regeneration" which is a box set of all the regeneration stories, including "The Tenth Planet", with a release date of June 24th listed. However, the box set also lists that animation was used to complete that particular story with surviving sequences where they remain.