So, why the Hell did they do it?
Why did the trailer last week include a Dalek extermination effect, thus giving the game away that the Daleks would be coming back as well? Why did they bother with it? The only event of the episode not leaked to the press - and even cut from all review copies sent to the papers - and yet they decided to do that one little effect in last week's trailer.
A wonderful episode anyway, of course, but I can't help wondering if the Dalek appearance would have been an even greater show-stopper if there was absolutely no clue about it beforehand.
Though how great would it have been if Chris Eccleston had leapt out of the sphere?