Wow, Halo 4 looks amazing! The graphics have actually been improved a massive amount, if you've ever seen the gameplay videos you'll know what I'm talking about.
The only thing I have seen about Halo 4 which I'm not too keen on is the fact that the first level is yet another jungle level, like Halo 3. When I play Halo, I expect the levels to be lush grassland, such as the level 'Halo' in Combat Evolved or the multiplayer map 'Hemorrhage' in Halo: Reach. However, I can put up with that, that's just a bit irrelevant.
I wonder how they'll keep the games in line with the story of 'Halo', involving the seven rings. Hmm, 343 have a lot to live up to!