We didn't randomly pick people, and we certainly didn't pick people based on their avatars :/
We've mentioned before that our main criteria was to ensure we chose both active players and a healthy mix of players when it comes to preferences in the game.
As for waves, I've addressed that in other threads but will also answer here - we don't have any current plans to do waves. Things can possibly change, but I don't want to get your hopes up in that respect.
@Cynthia, official forums
That makes it kind of scary knowing alex is in and Hans or Barton not.
Now I got shivers.