This is a combination of noun and verb.
Noun::: A.K.A. CoD Modern Warfare 2... only the most anticipated game that has dropped in, quite possibly, EVER!!!
Verb::: The act of playing CoD:MW2 and having an epic orgasm, or a wargasm. For a basic description of what happens while pwning n00bs in MW2, please see the Lonely Island video: Jizz In My Pants.
JCop::: Dude, are you ready for some Modern Wargasm all night tonight???
Ryzzle::: Guys, I was playing Modern Wargasm last night and had a modern wargasm.
DakOfDoom::: I just had a modern wargasm!!!