It would be nice to be able to create tournaments which bar players who have more than a specified number of ongoing games. If I had the choice I'd tend to avoid playing against anyone with hundreds of games.

It would also be handy if that info could appear as a number on a player's profile page rather than having to go to their Started Games page and download the entire list. This would be a boon to those on dial-up and could be a useful saving of server bandwidth.