Smart move Carmack. Smart move.

^I hope you are ironic

I am not sure exactly how MW2 will work but you basically got different guns and perks based on various statistics like wins, kills, kills with a certain gun, etc.  I am assuming these statistics will be tied to your IW.net profile and will be sent via some sort of messaging to an IW backend database after a match or during a match.  Depending on how IW is updating this information, it could mean playing on a hacked dedicated server would hinder the ability to update your profile.  If you are updating your profile information, they could possibly see that you are not registered as playing via the master matchmaking servers and could possibly tell that you are playing on hacked stuff.  Especially if this stuff is only updated when playing on a ranked playlist.  Not sure, but this could likely only be another small hurdle for hackers to overcome.

Dedicated servers here are speaking of state-less ones.

You guys understand that "lack of dedicated servers" doesn't mean "peer-to-peer", right?

It basically means that the "server" will be determined as the group of peers gets together, and will be "traded" to another peer, if the original "server" leaves the game.

This is part if IW's attempt to stop games from ending, just because the server left, which is something of a "cheating" mechanism for people playing on a dedicated host.

This way, yes, there will be a lag advantage, but it will probably be only for the guy who had the best (upload -- i.e. server bandwidth) connection to begin with (i.e. the guy would would have already had the lowest pings), and the rest of the game will be better off for it, because the best, of all players, would be chosen as the server, rather than some guy (who intentionally wants a lag advantage) with a cruddy connection.

Allowing the game to choose who the server is, is probably the best option for everyone playing, on the whole. The one, and only, better option would be to somehow guarantee that the dedicated server had colossal bandwidth -- in other words, was set up by a business, or by the game publisher themselves (like many of EA's games, like BF1943, or BF:BC, which have at least a few "big" dedicated servers, or Sony's games, like Warhawk, MAG, and SOCOM, etc, which are all "big" dedicated servers).

You are describing P2P.  That is exactly how Live/Halo matchmaking works.  Perhaps you are thinking we might be thinking distributed P2P with no single host box?  This P2P that is being talked about is still using the client/server model.  But there is no server involved, just a Peer that is handling all the other Peer's requests.

yes, this misconception that it is Peer-2-Peer is buggering me for some time. it's client-server, but the server also acts as a client.

but what you're talking about isn't related to dedicated servers. host migration is what will prevent a game from ending if the server leaves. with dedicated servers if someone leaves, another person comes in (and sometimes there are even people waiting in line to join). the only cheating someone can do with this is if the server resets the score when someone leaves and join again. it happens now with most games (although in UT99 and mods it didn't).

the host will always have advantage over the others because it's him that process everything and sends back to players. so let's say he shoots someone, then he must send a message to everyone telling it, but obviously he doesn't need to send himself a message. it would be even worse if the server had a bad connection, which is something the matchmaking service will try to attenuate.

It's a cold day in hell when John Carmack turns his back on the people who made him who he is today.  I'm not that surprised with IW since they act like a bunch of prima donnas anyway, but ID?

^Yes, it's a stab in the back.

Can you still create your own custom matches with custom rules, etc., and play against random people over the net?

Probably not the bolded.  Probably need to invite them to your game.