Are you referring to AEG's d10 3e version, or the d20 version? If the former, I'm definitely interested as a player.
As for DMing, I might be able to do that, though I have never run a pbp. I still have my notes from the last (face to face) L5R game, and that campaign didn't really conclude satisfactorily, since I had to leave to work in the outback.
Anyhow, if you get more interest I'd be interested in taking part.