Jumping miners created a real problem for Namecoin at the moment, they mined out previous set in 3 days when difficulty was low. After correction, network hash rate dropped 10 times leaving network with mining rate of 83 minutes per block, and the next correction projected
to happen in late November. When or if bitcoin becomes relatively weak to sum of alternative networks, then I think Gavin would have to change protocol so it will adjust difficulty much more frequent. I think we will see jump in bitcoin network hash rate right after next difficulty correction, and then decline after correction after the next.
I think i0coin retargets after 2016 blocks or after two weeks without retargeting. They should put that into namecoin.