Just reading some the LE threads and it has come to my conclusion that one feature that I think a lot of players might actually enjoy seeing is removing friendly fire when in a group. Not sure how hard it would it be to program such a feature but I think this could solve some of the more of the "oh crap I have No LE and we keep accidently killing our friends and oh crap my SL. and FUCK THIS GAME" moments lol.
Just an idea
EDIT: Or even maybe just a way not to be penalized if your in the same team. Though this could be griefed in a couple of ways overall this would make a few grouping people happy.