xhonzi said:

I think Tolkien changed his mind as to what Middle Earth was betwixt the writing of The Hobbit and The Lord of the Rings. The Goblin king, in the novel and all adaptations I've seen, seems to have just finished taking his afternoon tea when the party bursts in.

Tolkien definitely changed the nature of Middle Earth between the writing of the two works. Not really changed so much, as drastically grew and expanded upon it. The Hobbit was just a children's fairytale, while its sequel grew into a very large epic. In The Hobbit, the magic ring that makes you invisible was obviously just a fun little magical item. I remember really wishing I had a ring like that after first reading the book as a youngster. Of course, reading LOTR later my feelings toward the ring changed completely, and it no longer seemed like such a neat little item I wished I had.

Personally, I think the film did a great job of pulling The Hobbit into the universe of the LOTR films by feeling in the blanks and giving the whole thing a bit of a darker feel.

Still, as one of my friends pointed out, when you measure the escape from the goblins with the scene in the Mines of Moria from Fellowship, the contrast between the two films feel very severe. In The Hobbit, you never feel much concern for the escaping dwarves, you see them rolling around, falling great lengths, and bouncing around all over the place without any sign of injury. In Moria, you find yourself on the edge of your seat watching deadly arrow whizz past the heads of the fellowship, feeling real concern for the characters.