Sadly it's only getting worse. We are beyond a 24 hour retarget at this point. Even 24 hours is bad, because in reality all that means is that only 480 blocks are mined for each retarget period (~2 days right now). That's quite a bit shy of the target 1440 blocks that are supposed to be created each day.
Yes, some action is required here. I am researching the best retarget times now. So not to introduce other undesired side effects.
I am thinking now of 5 - 10 min retarget intervals. So we will do a hard fork in the near future to break this feedback cycle.
Titan
See if you can re-target based on time rather than block count, it should be pretty easy to do as each block has a timestamp so an "if greater than timestamp = x then adjust". Most devs take the easy way out and just change the block count parameter because it's easier to calculate when the last change occured, but just look at all the coins that have been high diff locked by the flash mining crowd to see that's pretty hopeless.
I think an elapsed time diff adjustment, like 10min, 30min, 1hr or more should be good, just depends on how long you are prepared to leave the block rate out of range. If you adjust frequently, say every 10min, then you could set a limit like no more than +/- 10% change every 10min. So the ups and downs are a bit more graceful.
If you went time based adjustments ask people to nominate the interval and the percentage to see whats prefered. You could even run a poll with some choices to see what miners want.
eg.
Interval Max diff adjustment
10min 10%
30min 50%
60min unlimited
...