Deserter "debuff"
I think it would be a great addition to a surrender option, to have anyone who quits a game (not by surrendering as a team) a "deserter debuff".
I got the idea from WoW, anyone who'd quit a game would be unable to join any for 10 minutes or so, this way players would be forced to use the surrender option, and not just quit.
And if someone is in a hurry or something it's ok if he quits, he wouldn't want to join a new game anyway.