Who: The Doctor's Wife Preview

This week's episode of Who is so shrouded in secrecy it might as well be a shadow, but we do know some intriguing details about what's to come in The Doctor's Wife and from what critics are saying it's a love letter to fans of the series so we're in for something special!
THE TITLE- What's that all about? The most obvious explanation is that Idris (the woman shown here), an apparently insane woman sentenced to death, either is the Doctor's wife from before the Time War or by some circumstances she becomes his wife- all we know is that the episode has nothing to do with River Song...
THE TIME LORDS- From the trailer, we can see that the Doctor is pretty pleased to find out someone else survived the Time War- but who? Is it the voice in the TARDIS who says "Fear me, I've killed hundreds of Time Lords", Idris, someone else entirely or is it all a cunning ploy?
THE TARDIS- We're going to see a lot more of the Doctor's time ship this week, including infinite corridors and David Tennant's TARDIS console room! But why?
THE OOD- Finally, there's the return of everyone's favourite telepathic aliens, as slaves controlled by the mysterious enemy by the looks of it- will they make use of their killer orbs?