AFAIK stuff like coop play isn't being worked on until they've got the console interface sorted out, but it isn't being left out. Voice acting, I'm not sure what's the deal: I suspect it won't be
fully voiced but I understand that there will be VA in time. The written dialogue would need to be finalised before they get the actors in, though.
It's still in the very early stages, there's plenty to come, so I wouldn't panic just yet. I share everyone else's impatience, though.