I have tried to contact Edena, who hopefully will show up on this thread soon. (He sometimes travels to different parts of the U.S., so he may be hard to reach at times.) He may wish to be involved, as the IRs were his idea.
I think we need to see what level of interest there is for another IR, how long people wish to participate, and make a decision on moderators. It might be wise to consider having more than one moderator, because of two issues: a tremendous amount of hard work and the time zone differences. As I write this, it is about 10:30 p.m. in the Chicago area. As I recall, Kalanyr is some 18 hours ahead of me. (I did fill in for Edena for one of the prep threads when I had a lot of time, and tried to adjust my schedule to help the European IR players. Let's say that it was a bit tiring.)
I think that a clear set of rules, or a keen skill for improvisation will be necessary for any moderator. I think what surprised me most about the 3rd IR is how inventive many of the players were in terms of strategy, political maneuvers, magic and military action. (Creamsteak certainly surprised a few people by keeping a much more powerful foe at bay.)
It might be best to have an established setting with magic. This would give people some common ground to work with, and provide them with sources of ideas for characterizations of nations and important characters. Also, it might help attract a few new people or a few old timers.
Uvenelei and Gnomeworks: Good to see you posting!!! I hope that both of you are doing well.