There were a lot of cute one-liners. I liked the Harry Potter references (three altogether?); the "57 academics" line (and pretty much all the Shakespeare stuff); Martha's reference to Ray Bradbury (which of course is particularly good if it's a nod to this year's overarching "Mr Saxon" theme); and the scene on the bed where Tennant's Doctor is being particularly alien, and Martha is hoping in vain that he will act human.
I wasn't in fact particularly grabbed by the witches. But I was prepared to go along for the ride.
Oddly enough I've been having a bit of a Tudor Who period in the last week; apart from this, I have been listening to the Sixth Doctor audio The Marian Conspiracy, which is set in the reign of Elizabeth's sister Mary (separate review coming up), and my own small contribution to fanfic, inspired by this exchange from The Sensorites. Funny how the Doctor seems to have had unseen quarrels with Tudor monarchs, rather than those from other time periods, isn't it?