Or... we just send them PMs asking if they still plan on posting, and if not, do we have permission to kill off their characters? I think that's a bit simpler.
Personally, I think there should be a rule in an RPG that if your character is inactive for an extended amount of time (unless you've already given reasons for your absence and intend to return), then they become fair game for the other member of the RPG, and that means killing them off if they deem it appropriate. ;D
That being said, I think we should at least attempt to contact JT and CEB first. Just out of courtesy.