What if they are just statues? They didn't attack Amy and the Doctor when they entered the building titled 'Winter Quay' during filming and didn't move (these were just the statue models though).
On set of filming it has been revealed that will almost certainly get to see the weeping angels move once more, maybe not with people seeing them move but we will almost certainly see it on the TV, as the following image shows.
On this photo that has been taken it is showing a camera, fixing its position onto a (half white) half silver sphere, this is commonly used to show the shadow and the lighting of an object that isn't actually there (that is usually put in with green screen afterwards).
The last time we saw CGI in relation to the weeping angels was at the point in 'The Time of Angels' where Amy was in the forest and the angels were starting to move.
Could we be in for another round of 'moving angels'?
Only time will tell....(or a trailer showing it!)