Some really cool halo 2 info:

New Maps:

Midship - A Covenant Cruiser.
Ivory Tower - The Top of a giant Skyscraper.
Waterworks - The Stalagnites on the screenshots are destroyable, they can even destroy a Tank if they fall down.

New Weapons:

Covenant Carbine - A Covenant Battle Rifle.
Covenant Energy Sniper Rifle - As the name says.
Brute Shot - A mortar that fires 4 grenades that explode on the second impact.
Pistol - You can use 2 at the same time, thats the only info on this weapon.

Vehicles:

Banshee - The Banshee can do "Loopings" and it can spin around if you hold down A + Directional Buttons. A Banshee can be boarded while it is flying.
Tank - The tank has a new control layout.
Boarding - Only Brutes and Elites can board vehicles, the Grunts an Jackals don't are intelligent enough to do it.

Controls:

The white button is a Team Speak button now, the flashlight is no more. The Directional Pad can be used for Tricks in combination with the A button.

XBL:

- There will be a ranking system.
- There will be DLC, including new maps and "more".
- There will be a Feature called "Virtual Couch", you can play with a buddy and if he leaves the server you will automatically follow him.
- There will be Sword Only gametypes that are really cool.