Looks like Modern Warfare 2 may be the first to do away with the party chat while playing their game online. Microsoft has given developers the right to turn off party chat while playing multi player games. Why you may ask. Well cheating. People use the party chat to tell their friends were the enemies are on the map.
While I can see this as being a problem turning off party chat would not be cool. I know I'm always in a party chat while playing. Most of the time it's so I don't have to listen to the other knuckleheads I'm playing with. The language and insults that fly over XBL are outrageous. If you are looking just to have fun and a good time then party chat is the way to go. It will be interesting to see how long this last or how many other games do this. Personally I think that this will not last long but until then you will have to chose to talk with friends or play online.
Source thanks to Bullethound for sending me this article.