Multiplayer is the same as it was 2 years ago.
Cooperative with up to 4 players in total.
I recommend to set your options to “invite only” and just to play with friends/people you know.
Additionally, sadly there are currently some critical bugs in multiplayer that cause crashes. For example if you try to complete the story together with friends, the progress just is saved at the hosts safegame.
Oh, two more important new features:
new game+, which offers now up to 4 “worlds” for your 4 characters. So you can now restart the story and map without deleting your safegame and play with your existing character(s).