I was one of the nerds who ended up watching the Fallout 76 presentation at E3... here is my take away:
1) Multi-player: Yes. MASSIVE-Multiplayer: No.
Essentially the game is online only (Boo) and will allow you to invite up to 12 (?) people to play with you... they did say that many challenges are geared towards groups and not, if I recall, not auto-leveled to the number of people.
2) The world will be roughly 4 times the size of Fallout 4, set in West Virginia in the earliest moments of survivors emerging from the vaults. This world will be mostly inhabilited by mutated creatures rather than warring tribes and mutants.
3) It is an open ended survival world where "you make the story". So, a sandbox.
4) Your character and levels will transfer seamlessly between your version of the world and worlds create by other people. No starting over in order to join a new world.
5) The highlight of the presentation was a prank "first look" at "
Skyrim Echo", the first version of Elder Scrolls for the Amazon Echo:
Alexa: (paraphrase) "He ht's you for significant damage"
Man on Couch: "Alexa, take a health potion!"
Alexa: "You are out of health potions"
Man: "Do I have any cheese?!"
Alexa: "You have 104 wheels of cheese in your inventory"
Man: "Alexa, EAT ALL THE CHEESE!"
Wife: "Alexa, wait. Honey, don't you remember you are lactose intellerant?"
Man: "Right, thank you baby. Love you."
Man (angry whisper): "Alexa... eat. all. the. cheese!"
:lamo
I'd totally play Skyrim Echo.
And... 6) One of the Group tasks you can perform is gathering launch keys scattered around the map that when used in unison can unlock one of several nuclear silos around the map, allowing you and your friends to send a nuclear bomb to devastate anywhere on the map that might offend you. Doing so levels the area, creates much more difficult mutated monstrosities, but also uncovers valuable resources needed for high end crafting.