I think that the whole exclusionary system is a bad idea, if people can host, power to them, don't stop them from doing something they can do in every other game. That aside, I do think that there should be settable filters, a favorite server system, and a ban status would be nice as well.
I also imagine a versatile friend/clan system would be good, especially useful when you want to know what server a friend or clan member is on. Some of these features will probably be in the next RTB. Regardless, many of them would be nice things to implement and would make it so much easier to tell which server you would like to join.