The 1 block retarget, 36 block SMA, with a 12% up/down limit has been tested on the testnet and has reacted very smoothly and quickly to rapid increases in hash rate (we started with instantly adding 20 times more hash than base, then increased that last night.  This fairly closely simulates the current low hash rate and the injection of computer power by switching pools we've seen to date.  The difficulty and block times are responding very well.  Most importantly, this eliminates the massive difficulty swings that have brought coinhopping pools to us in the first place.