Call of Duty is a great example of a game that became as popular as it did due to having a good (above average, honestly) voice chat system. The game >IS< all about PVP and so trash talk seems to come about anytime pvp happens. On "Zombies" there is a cooperative aspect and much less trash talking aside from the "elitist" players who can't handle things not going perfectly. You'll always have trolls and elite players and like someone else mentioned... blacklist, mute, squelch, etc is perfect for those people.

I just paid $41 for another 3 months of this game and so I could get that flying mount... I'm sure I'll be seeing a lot more of those flying mounts this whole week...Imagine if a small portion of everyone's $41 was put into a good chat system.