As the Beeb announce their Christmas goodies today, one of the items is a new promo pic for the Doctor Who Christmas Special, featuring as yet unseen 'creatures' that look like Angels. Something of a cross between the Weeping Angels from "Blink" and the robot Santas from the last two festive episodes is my first impression.
Meanwhile the other buzz amongst online fans has been the Mirror story of a series 4 return for Rose coinciding with photos from recent filming which appear to confirm this. Graeme Harper's appearance in one of these shots would appear to suggest this is for the Doctor-lite episode making up Block 7. This also follows similar reports of Lis Sladen also being on set with Catherine Tate. In otherwords the rumours are that the episode will be Doctor-lite, but companion-heavy with four of them (Rose, Martha, Donna and Sarah) appearing. The Mirror story also says Billie Piper is there for three episodes. And since we also know Captain Jack is back at some point there may be five companions (I feel a story title coming on!).
I put this item in because I'm fairly sure all this speculation is on the right track, partly because Billie is wearing a very Rose-like outfit, but one we've not seen before.