Some info about Fallout 3:
They'll handle the ending as a dynamic cutscene that changes depending on specific decisions you make. Right now there are over 500 variations of the cutscene. You can talk to Dogmeat although he only barks and wags his tail. But they say you always tell if he agrees or disagrees with you. There are no guilds like in Oblivion. You just go around doing different quests for various groups. The world is entirely open from the start although certain areas can be difficult at the start. There will be licensed music from the 40's and 50's. Songs and artists include Ink Spots"I Don't Want to Set the World on Fire", Bob Crosby's "Way Back Home", and Roy Brown's "Butcher Pete". There are no vehicles. The game has gotten bigger since the initial announcement. They've had to remove some features but they say they weren't anything they'd officially announced.