I was actually considering the game. Then I read this.
"Curious players have also wondered about how Dark Souls on Xbox 360 will handle Party Chat and Private Chat functionality. Well, the game does not support player-to-player voice chat over Xbox Live. At all. No real surprises there. However, if players engage a Party Chat session, Dark Souls will instantly kick you out of your current game and boot you to the main menu."
Then I lol'd.