Peter Molyneux is on right now talking about Fable 2. You can instantly, with no menus or complications, invite your friends no matter where you are in the story.
I am watching on IGN Live Stream -- RE5 actually looked really good. I liked the Coop demo gameplay. But it was easily downshot by the shoddy gameplay of the people who were demoing it. The one playing Chris couldn't snipe for crap lol