Someone is still adding a boatload of hashing power to the network and difficulty is still going up ~20% every difficulty increase.

I thought the difficulty increases would slow down after Knc finished shipping their November batch since 28nm miners from other manufacturers have been delayed.

http://bitcoinwisdom.com/bitcoin/difficulty

Does anyone care to speculate on who is adding all the hashing power at the moment?

The Bitmain Antminer batches seem too small to have a huge impact. I thought BitFury was basically waiting on more chips to be manufactured. AsicMiner doesn't seem to be doing much. BFL has overpriced 65nm products in stock, but I can't imagine that they are selling many. Avalon Gen2 chips are power hogs.

Where is all this hashing power coming from?