My buddy and I both received this game for Christmas. While we have yet to play together on-line, we have been talking about the missions.
The third mission in is despicable. The game asks you at the start, and again when you get to this mission, if you want to skip it. It involves a serious moral question. I'll not give it away on the forum, however, if you want to send me a message, I'll let out some details.
Overall, a good game, with the newest weaponry. I look forward to playing on-line with my buddy Josh tonight.