There’s lots of material to use, more than just “There and Back Again”. Sounds like they’re going to tell some of the other stories and legends.
It could get out of hand. But I’ll be happy if they just get TABA right... the rest, mostly in the sequel I hope, is just sauce.
Or... they tell the other stories in flashback, interwoven through the basic TABA story, so we don’t meet Smaug until the second movie. Dang... I’ll bet that’s what they do.
What I’ve heard is they think there’s a lot of history between the “A” story of the Hobbit, and the beginning of Fellowship, and there is. Much of it is just alluded to in the books, or buried in the Appendices...
Not sure how they’ll weave it in, but there’s meetings of the White Council and the throwing the Necromancer out of Mirkwood, there’s Gandalf and Aragorn searching all over the place for Gollum, and finding that he had already been to Mordor and spilled his guts.
I don’t know how they’ll weave it into the story... Lots of “meanwhile” cuts, probably ;~)
I take your point, but it's risky. There are fragments of Middle Earth history of the period referenced in the published canon -- Gollum's wanderings; Aragorn tracking Gollum; the White Council driving Sauron from Dol Guldur; Aragorn's romance with Arwen; the dwarves' war with the orcs -- but nothing developed as a story by Tolkein.
Pretty risky territory. Strikes me as similar to that Gone With The Wind sequel a few years back.