"Very good Fili. Thank you for your input. Now hush, the grownups are talking."
The Book: Bilbo offers a little light, but the dwarves (all in unison), demand that it be kept dark. Thorin is long-winded, and begins his speech with various empty pleasantries. Bilbo, at being called a "fellow conspirator" who "may never return" shrieks. Gandalf strikes a blue light on his staff so the dwarves can see Bilbo crouching and shaking, so they laid him out on a couch. After a while, he returns to the dwarves talking about him. Hearing Gloin insult him, Bilbo promises to do whatever needs to be done. Gandalf claims to have chosen Bilbo as the 14th member, but if the dwarves dislike him, they can "stop at thirteen and have all the bad luck" they like. Then he requests some light, which Bilbo supplies. Gandalf shows the dwarves the map, and points out the runes that mark the secret entrance. The party discusses how Smaug could not have found the door, it being too small for a beast of his size. Gandalf produces the key, and gives it to Thorin, who promises to keep it safe. Thorin plans the route, and mockingly suggests that Bilbo offer some advice. Bilbo asks instead what he's getting out of it, and wants some details about the dragon, which Thorin provides. He mentions the death of his grandfather Thror, by the hands of Azog the Goblin in the mines of Moria. Gandalf tells Thorin about his father, Thrain, who he'd found in the dungeons of the Necromancer. Thrain couldn't even remember his own name. Gandalf only found him by accident, on some "nasty dangerous business," and warns the dwarves to stay away from the Necromancer - a being far beyond the powers of all the dwarves in the world. Bilbo decides to put an end to the meeting, and promises to give everyone a good breakfast before they go (though he's so annoyed, he quickly decides that maybe he won't be making their breakfast at all).
Hobbits are good at hiding, finding rings, and being passive aggressive.
What does it matter? This is a conversation much heavier on exposition in the book; they learn about Smaug's attack on Erebor, Thror's death by Azog, and Thrain's captivity at the hands of the Necromancer. More important than what the movie leaves out, however, is what it decides to put in, namely the "portents" that Oin has read, and Thorin's meeting with the seven kingdoms. There are no such portents in the book. None of the dwarves claim that there is any specific signs or guides saying that now is the time to move. The meeting at Ered Luin also never happened. This is significant because Dain is specifically mentioned as having been present. Dain lives in the Iron Hills, which are far to the East - on the other side of Erebor. The entire story of The Hobbit involves, essentially, the travel from Point A to Point B. Knowing that Dain Ironfoot, Lord of the Iron Hills, was making the same journey east at around the same time as Thorin's company raises some questions that the movie fails to answer.
My Opinion: The meeting in the movie seemed far more fluid, natural, and cohesive than the book - which was honestly rather all-over-the-place. Putting bits of exposition elsewhere in the story (Smaug's attack in the prologue, for example) allowed the audience to learn the backstory of the dwarves just as well, without forcing several bits of disjointed exposition down their throats. The details that were added, though, did more harm than good, especially that bit with Dain. In addressing the potential issue of "why don't other dwarves help?", Peter Jackson just raised a host of other issues that are left unanswered. Why didn't they travel together? What was Dain doing in the Blue Mountains? Why did he refuse to offer some assistance? I'd rather Peter Jackson had just left the matter alone. The portents that Oin saw were a nice touch, but pretty unnecessary; they, too, raise some weird questions. Are there more to these signs than birds returning to the mountain? Why do the returning birds signify that Smaug is done or dead? Who made this prophecy? Again, had Jackson not created this detail, there wouldn't be a reason to ask these questions - but he did, so there is.
A small thing that I was sad to not see present was the mention of "luck" as a factor in Bilbo's inclusion in the group; namely, that he was chosen so Thorin's Company would number 14 instead of 13 (Gandalf not included in the count due to his propensity to come and go as he does). The movie does make mention that Gandalf was asked to "find a 14th member," but it doesn't say why - the book makes it clear that the dwarves do not want the number of their company to be an unlucky number. It comes up in the conversation between Bilbo and Smaug that he was "chosen for the lucky number," and without including that minor detail now, it's just something that won't quite have the same impact in the movie.