You forgot the bit about the white council saying, lets' go beat up the necromancer, Sarumon saying, no, since he wants the wait for the 1 ring to reveal itself so he can grab and claim it, later on Gandolf saying I found proof that the Necromancer is Sauron, the rest of the council, except Sarumon saying, let's go beat him up. Sarumon saying, fine whatever. sauron shrugging and going back to Mordor.
They may also show more of Deagol and Smeagol, Gandolf meeting with the Dwarves and talking them into going to get their kingdom back from the dragon.
I don't remember the details but there was a bit about Gandalf meeting with the dwarves before the hobbit starts, in the book Unfinished Tales. I think Tolkein's son said his father had intended that story to be a chapter in the Lord of the rings, forgot which book, where I think Frodo asks Gandalf how he happened to pick Bilbo or somesuch and Gandalf tells the story. But I think his son said his father cut the chapter due to it making the book to long or something. Don't remember the details, been decades since I read it.