So it took a while, but leaving industriousness to those with the skills usually bears fruit.

The fruit in this case is an iw.net emulator that you can run on your machine to validate a fixed mp exe against. We at MW2O have not tried it, but know someone that has and reports are that it works perfectly allowing multi player games to be hosted on even the newest maps, with gametypes that are not yet open to the public.

Well done guys, now people at lans without internet connections can play the game. And more. Why was this not shipped with the final version again?

http://alteriw.net/viewtopic.php?f=3&t=24

All the info needed to see what it's all about is there.

Cheers!