I've been a part of Halo-GAF community since Halo 3 and a fan since day one. Brush up on your Halo-GAF lore.
I don't like Halo 3's box art but that has nothing to do with the quality of the game, I adore it.
This boxart is just fine and I think it gets you excited that MC has crashed landed on a weird and mysterious planet. But I think the old design adage "less is more" applies here and I would have liked less commotion going on in the composition. This has nothing to do with the quality of the game itself.
The art looks fantastic; always has. I've just never been drawn in by the lore... Perhaps they'll strike a more interesting chord this time around. The GI article talked a bit about what they were trying to do, the characters, etc. and it sounds promising. I just know me and a buddy co-op'ed Halo 3 and I never wanted to play it again after that.