There are some new photos online from the recent filming in London over the past couple of days:
The World Entertainment News Network site has a second collection up with four pages of small photos (the large ones are not available except as highly watermarked files) including Tennant and Piper leaving the TARDIS, Billie under an umbrella, and Noel Clarke, all in a rainy environment (possibly the opening of the Christmas special).
The Czech Isifa Photo service (again reproducing images from the international Splash News celebrity picture service) has added more images including a snow-dusted TARDIS, Piper and Clarke running, Coduri and Tennant outside the TARDIS (again, images watermarked by the photo service).
Our friends at David-tennant.com have a selection of small photos taken of Tennant and Piper together.
The Unit News site has a collection of photographs taken at the Brandon Estate, site of Jackie and Rose's flat used in the first series and again in the Christmas special.
UPDATE 2030 GMT: Another site, Xposurephotos (yet another news photograph site) has more pictures online from the filming over the past several days.