Atleast we know ONE Multiplayer mode. Also it seems during multiplayer we can have a specific gun equiped, rather then finding them on the floor like AVP3. Also it is likely it will allow us to aquire the Smartgun and Flame thrower early, and given the fact that it said Pulse Rifle UPGRADE instead. It MAY be possible that those weapons are skins for the one's in the game (Like we may have a slightly different varient of those weapons in the story mode, but im just guessing)
Im gonna try and save up abit more for the CE, I've already got my money to buy the normal edition.