Already got it, already beat it. On second playthrough.
The release date got broken out here by three days. I noticed them in the protected cage by the cashiers and casually asked if I could get a copy trying not to hyperventilate in the process- I was stunned that they actually gave me one. Paid for it and ran out of the store as fast as I could, when I went back the next day to buy something else they'd already been pulled.
The graphics are fantastic, a true indication of what you can do when you write your own game engine and push the limits. The character animation is top notch and I swear the facial animations are better then anything I've seen in any game. Voice acting was amazing. The story was OK, you should probably read Halo: Cryptum and Halo: Primordium if you want to know more about the history stuff (the books really sucked by the way, but that's what Halo 4 ties into). The ending was seriously anticlimactic/disappointing and a bit whacked though.
I still think Halo 1 was the best game, as far as story goes. For everything else, Halo 4 is definitely the best of them all. But the graphics and audio, my god, those two together basically override any other shortcoming. I would even say that it has to be one of the best looking 360 games ever produced.
-SC