Just for the record, this year's D[octo]r Who[?] Christmas Special was quite good. However, the sheer weight of refrigerator logic problems got to be a problem by the end. And lampshading the big one didn't actually help.
(Yes, "recent Dr Who episode suffers from logical coherence problems". Please try to act surprised.)
Sorry about all the geeky jargon there.
Anyway, if we're going to spend time and effort discussing the chances of supporting cast from previous episodes becoming the next Doctor - is it too late to start a claque for Dervla Kirwan?