All versions of
Call of Duty: Modern Warfare 2 have some issues causing the experience to not be up to snuff. I've run into various connection issues during some multiplayer sessions and there's been reports across the other versions that they are having problems as well. Robert Bowling
tweeted that they are in the process of working on their first major update so let's hope it comes out soon.
I finally got into a game last night where one guy just dominated and launched a tactical nuke on everyone. Good thing he was on my team but he racked up kills at a pretty quick rate and finished with 55. The game pretty much ended at around the 7 minute mark when the nuke was deployed.