I've seen leaked content, but I don't care. I love seeing gameplay of the MP maps, and Forge. But for Campaign, I refuse to watch anything for it. I didn't even watch the demo that Bungie played at Gamescom. I figure that with MP, it doesn't matter if I see the maps or not, because I'm going to play the game for years. With Campaign, you can only experience the story once, then it's not as fun.