Sledgehammer has posted some notes on C&C 3 he wrote while at E3. His primary news is in the campaigns:
Now what I am about to say can & could change as the game is in very early development. Each of the 3 factions will have a single player campaign. You will have to start with GDI and work you way through to play all the factions. But EA is taking each faction and splitting them up into what they are calling theaters and each theater will contain between 4 to 6 missions. The cool part is they are tying the story line into each mission. So lets say you just attacked a Airfield as your primary objective, so now in your next mission the Airfield will be useable or will be used in some way within each new mission as you move forward. Also you get to choose which theater you want to play, allowing you to change up the way the story plays out, or which order the story is told.
More
here.
