Block spacing appears to be steady in a range of 30-40 seconds, the increases in difficulty are keeping it in this range for now. However, if an optimized miner with a large improvement in prime generation speed was released (ahem luke-jr's BFGminer) then I would expect to see a block spacing of ~10 seconds and the difficulty would take days to catch up.
Too bad nobody is doing altcoin releases sensibly in this area.
There should be a minimum difficulty set high enough that it doesn't go through a rush like this.
Bitcoin didn't break difficulty 1 for months (if not longer).