I've player 1.5 matches online and I'm now ranked 2.2 million in the world. 2.2 million people are playing multiplayer about 24 hours after launch. And that's just the Xbox 360 version.
To put that in perspective, Halo 3: ODST sold 1.2 million units in it's first month. MW2 doubled that in a day. Holy shit.
EDIT: To clarify on the 1.5 matches thing: In most of the ranked multiplayer modes you can't use Xbox Live party chat. (Party chat is like having a private chat channel for you and your friends, instead of using the in-game chat. Like running vent while playing a PC game instead of using in game chat.) You can't use party chat because that could lead to dead people telling enemy locations and such. So I started in a party with a friend, and it forced us into game chat when we joined. Then when my friend got frustrated and sucking ass at the game, and turned off his Xbox, my system tried to reconnect to party chat, the game detected it, and I got booted from the game.
I understand the reason for blocking party chat, but it could have been handled better. There needs to be a quick option to mute anyone not on your friends list, also keeping them from hearing you. Random people online are retards and I don't want to talk to them. I want to talk to my friends though.
Yea and apparently my friend just sucks at the game, and didn't expect to. He talking about taking his game back and selling his Xbox now rofl. You can't expect to be a god when the multi has leveling up, and at 1 we were facing level 20+ people. They've got more experience and better equipment options.
EDIT 2: OK it seems you can go into your profile options on the 360 dashboard and set chat settings to friends only. It doesn't prevent the screwy kick from game I got, but it makes in-game chat friends only.