Well, it's already a pretty common practice to ban idiots who break the rules on message boards and other online communities, so I don't really see how this is a problem. I mean, technically, this sort of behavior on Xbox Live has been cause for ban for years. It's just not well-enforced.
Of course, I guess the gamer gaters and free speech warriors will take needless offense to this like this is some kind of new concept.
As for potential abuse, I doubt anyone is going to be outright banned based on one complaint from a single player. It's much more likely that it will take constant reporting from multiple players about a single person before that happens.
Really, unless you are a persistent ass online, you should be fine. And if you are, it's probably better for others to not have to deal with you.
