Actually pretty excited for it. I'm really satisfied with the graphics upgrade, looks like a clean evolution of Halo 3. Their choice to go back to the classic Halo look is very appreciated, because the art direction of Halo 5 (and to an extent H4) really shit the bed, making them feel not authentically 'Halo'. It's really nice to have the classic Scorpion tank, battle rifle, Covenant, and Master Chief armor back.
In terms of game design, i'm slightly concerned about the new abilities. I've made my peace with things like sprint being in the game, but that new grappling mechanic and the new power.. items (the skulls?) look potentially over-powerd. I just hope the balance is decent.