Well after seeing the commercial, I'm certainly very excited for the game to debut. Bungie had said last week that the trailer is full of little hints and goodies for us fanboys to enjoy, and thus far, I've spotted a few.
1) Spot number one is the two kids sitting in the grass. A long-distance guess is that it could be John 117 before his entrance into the SPARTAN program, of which he became a part of at the age of seven, but that is pure speculation on my behalf.
2) John 117 looks rough, and he has been getting his ass-kicked, thats pretty clear here. The Covenant appears to have had a more than successful attack on Earth, and it looks as though the game will be played in a very defensive way. The new shield system looks pretty cool, and it will be interesting to see how it fits into the game.
3) The new weapons system is apparent here, where you carry your secondary weapon over your back. The 'Chief has the updated Assault Riffle in tow, which is surprising, as you would figure he would have had a secondary weapon of some kind as well.
4) It is a certainty that the brutes are the bad-guys here.
Does that mean the Elites side with the humans?
5) This game is going to kick-ass. There isn't any questioning of that...