There is an interesting article about the second installment of Peter Jackson's The Hobbit trilogy in theatlantic.com by Christopher Orr. And I agree with everything Orr elaborates on. . . :/
Here's an extract:
There are two obvious ways a director can go wrong in adapting a work with a large and ardent pre-existing fan base. He (or she) can feel so constrained by expectations that he makes his adaptation too literal, a book-on-film. Or he can get carried away riffing on the original story, pulling in references from related works and assuming that fans’ appetites for additional material are, for all intents and purposes, insatiable. Peter Jackson's Violent Betrayal of Tolkien
As a general rule, I think the former temptation, over-fidelity, is the greater hazard. But Peter Jackson’s The Hobbit: The Desolation of Smaug is proof that when you go the other way—really, really far the other way—the result can be genuinely egregious.
And yes, before we go further, I’m well aware that this meeting is cited in The Hobbit, and that many of Jackson’s other additions and digressions are part of the larger Middle Earth canon. But despite the fact the Tolkien went back to amend The Hobbit more than once, he never chose to cram in all this supplemental material, because the book was not intended as a sweeping, multifaceted epic, but rather as a more personal, hobbit’s-eye-view adventure story.
Whether through ego, avarice, or unchecked enthusiasm, Jackson has entered deep into the realm of fan fiction. Indeed, having granted himself boundless license to reimagine, he seems to have begun reimagining even his own reimaginings. The hideous orc leader relentlessly pursuing our heroes whom Jackson introduced in the previous film, Azog the Defiler, is in this movie replaced by a different hideous orc leader relentlessly pursuing our heroes. (This, in turn, frees Azog up to lend his hand to some pre-LoTR backstory embellishment.) At some point this level of constant reinvention threatens to become not only self-reinforcing, but self-consuming. Where does Jackson go after he completes his expansive re-telling of The Hobbit? Will he reissue The Lord of the Rings trilogy with new material added to reflect the canonical changes he’s made here? (The real reason that Legolas dislikes dwarves is…) Will he adapt The Silmarillion? Or will he retreat from view to tinker with his High Frame Rate toys? Whatever his decision, Jackson has by now laid to rest any lingering doubt that he is, indeed, the new George Lucas. Congratulations.