No Jeff in Warzone, but he of course remains the announcer for Arena. For Warzone we are presenting the mode as more "in-fiction" - it's a simulation of battles from around the Galaxy. So the Warzone commander (Palmer, for any of you eggheads who didn't recognize her) gives you updates on mission status, objectives and in-session progression.
Absolutely, without a doubt, the biggest ensemble cast in a Halo game yet including new and returning characters. That's not even a complete list.
Meow?
The campaign demo we showed was a small section from one of the missions in the game, carefully recrafted to show off some of the new features. We also modified narrative to minimize spoilers.
I know you guys wanted to see open, sandbox gameplay, but that doesn't demo well, especially within tight time constraints for live television. The H5 campaign features the biggest, most open campaign spaces in any Halo game and has been designed with many options and different paths to support cooperative play. If you like open, sandboxy Halo with lots of exploration and replay, you will not be disappoint.