It was only a Teaser trailer, but holy hell that sent SO many chills down my spine it was ridiculous.
Looks like there will be Armor Abilities, as well as a new gun and gun attachments.
The new gun is a single shot explosive weapon, and at the end of the Teaser he hooks on some sort of silencer barrel. Or it looks like he could just be reloading the single shot weapon, I'm not sure!
It was also announced to be a trilogy of games. I am so freaking excited for this. Finally, back to a real emotional storyline with main characters and no more spin offs. A real Halo game (Not to say ODST or Reach weren't real Halo games, but they were just spin-offs... albeit the best spin-offs I've ever played).
GAHH This whole next year is going to kill me. I haven't been this excited for a game since Halo 3! (I wasn't as excited for Reach because I'm older now with a lot more responsibilities and more stuff going on than just school/videogames)