In a press release regarding their 2013 commissions, the BBC have promised:
The Village, Ripper Street, Luther, The White Queen and the Doctor Who 50th Anniversary Special. These shows will bring a rich range of tones and worlds to BBC One's fiction.Indeed they will.
I suppose there might be semantic question about what "special" means. It could be a "special serial," I suppose.
Or maybe there will be multiple episodes, just that most of them won't be "anniversary specials" per se.
I reckon we can probably take this on face value, though. Bleeding Cool had heard there would be "more than one," but I'd now hazard a guess that the other special being referred to there is Mark Gatiss' drama about the creation of the show.
Incidentally, there's a lot of other things on the slate that look appealing. More on some of that, imminently...