i bet halo 4 would be fantastic on PC! I would defiantly buy, it has become my favorite. Halo 3 was meh, but with 1080 and aax16 sounds awesome!, i would buy it on steam. However i think PC could really use some halo love!
I just know M$ will make me put win 8 back on to play like with craptastic vista for halo2, which i never played because vista was an os abortion which win 8 isnt far behind tbh.