Post history, temperament, english proficency and a number of other factors go into who becomes a moderator of a forum. English proficency doesn't really apply here though, from what I've seen.
I am sure there is a thread or chatroom where the people involved are discussing this. It is not an easy decison, I can assure you guys. I helped pick new moderators at a forum, and when the possible canditate pool is 200-1000 people, picking just a few is not easy. In due time, in due time!
I am confident that Alex and Co. will pick good moderators.