I have not seen any unusual activity on the TEPCO webcams since emissions settled down in October after the 6.0 earthquakes off the coast (last update here and discussion of earthquake here).
Over at Caferadlab, Horse and other watchers have noticed and screen-captured "sparks" (see here). I've seen a few myself over the last couple of weeks, but haven't been successful capturing them.
Here are some recent screenshots:
Yesterday