If you have 30 minutes listen to it, its worth it:
Highlights: The Library will be easier to navigate with good graphics
The Multiplayer is in the reach engine, but you do not need a copy of halo reach to play it (no two disks) But those playing multiplayer on Halo CEA will be playing online with those who have chosen to download the maps to reach.
Listen Here
http://halo.xbox.com/Content/assets/en-us/Podcast/343Sparkast _004.mp3