I had to check to make sure Ursus-Veritas didn't already beat me to it, but I haven't seen these Doctor Who set pics posted yet.
They were apparently doing a night shoot out at Puzzlewood last week with a lot of fake smoke and snow covered trees. It was rumored that this shoot might have involved Weeping Angels, but the actress who made the original tweet (and played a Weeping Angel in the past) has since deleted it, and claimed it had nothing to do with Doctor Who.
There was also supposedly some snow-covered filming taking place at the Sennybridge Ranges, with exploded Daleks, and making use of some real life derelict tanks left over from the Falklands invasion. (which is a pretty cunning bit of location scouting for someone looking to replicate a war-ravaged wastes of Trenzalore on a BBC budget)