I feel like the difficulty retarget time needs to be reduced dramatically. Take a look at catcoin, and ronpaulcoin. As soon as a multipool hits this coin, they'll mine until next retarget, difficulty will skyrocket, they'll leave, and then there will not be enough hash left for us to meet the next retarget time.

Its far better to set retarget time to something like ~54 instead of 540 blocks, and to limit the change to 10% or so instead of allowing it to jump 5000% because one multipool joined in for a few minutes.  This can be handled otherways, this just seems like the easiest way to have a smooth difficulty retarget.

Every coin i've seen with a retarget this high either forks 2 weeks after launch or dies.