This is a comparison between the Theatrical Edition (from a German BluRay) and the Extended Edition (from a UK BluRay)
31 differences, including:
* 6 alternative scenes
* 3 scenes with changes in editing
* 3 digitally edited scenes
* 3 scenes where the theatrical edition is longer
Difference: 1514.5 sec (= 25:15 min)
* Additional material in Extended Edition: 1611.6 sec (= 26:52 min)
* Additional material in Theatrical Edition: 96.9 sec (= 1:37 min)
The process of analyzing of Peter Jackson's films about J.R.R. Tolkien's fascinating parallel universe has already been described in the version comparison of The Hobbit: An Unexpected Journey. As nothing really changed, and the process of publishing the Extended Editions (like before, a good year after the theatrical release and right before the start of the 3rd film) is well-known by now, let's just plunge into the main part.
The running time difference of roughly 25 minutes allows for quite much added material this time around. In fact, the Extended Edition is a much more an improvement on the movie, than it was the case with its predecessor. The complete runtime of the new scenes is actually even longer, because some small bits from the Theatrical Edition have been removed as well. However, these missing pieces are not that relevant, as their respective themes are fleshed out more in the added material.
The most prominent scenes add more character depth. Beorn, whom we encounter only briefly in the Theatrical Edition, has two longer scenes demonstrating his strength. Also, we gain some insight into the power struggles in Middle-Earth - and, well, the scenery of New Zealand as a backdrop of these scenes is also gorgeous. Several longer dialogues between Alfrid and his Master in Laketown have been added in order to flesh out political interests of the different parties involved.
Also, there are several flashback sequences, especially in the beginning and in the aforementioned Beorn scenes. They also provide better context for the epic story. The entombment of the Nazgűl leader is shown and the battle from the previous film (where Thorin's father Thrain is supposed to have perished) is referenced several times.
The last issue of Thrain plays also a further role, if you consider the curious fact of digital retouching: only in the Extended Edition Gandalf gets to meet Thrain in Dol Guldur - he had survived and has apparently lost his mind. When Azog attacks, there are several identical shots - however, Thrain is only present in the Extended Edition. And while it is nice to finish this storyline, it still appears to have been done rather hastily. Thrain is killed off rather unspectacularly, and after that Gandalf does not mention his temporary ally in any way. Therefore it is understandable why the filmmakers chose to entirely remove this character from the Theatrical Edition.
There are some more extensions, some added lines here and there. Also one should point out an additional sequence in Mirkwood which adds up to the psychedelic atmosphere which had been beautifully described in the book. Also, we get to see a much discussed scene involving a a white stag here.
The runtime is specified by the following scheme
Theatrical Edition Blu-ray / Extended Edition Blu-ray
03:27 / 03:27-04:49
The dialogue between Gandalf and Thorin is longer. There is a flashback to the battle from Film 1, where Thrain tries to persuade Thorin not to pursue Azog after he killed Thror.
Thorin: "You're like the others. You think he is dead."
Gandalf: "I was not at the Battle of Moria."
Thorin: "No, but I was."
The flashback starts and we hear Thorin's voiceover: "My grandfather, Thror, was slain."
After Azog throws Thror's head on the ground, Thorin cries: "No! Father."
Thrain: "Stay back."
Thorin: "No. I will fight with you."
Thrain: "Azog means to kill us all. One by one, he will destroy the line of Durin. But by mine's life, he shall not take my son. You will stay here."
Again, Thorin's voiceover: "My father led a charge towards the Dimrill Gate. He never returned. 'Thrain is gone', they told me. 'He is one of the fallen.' But at the end of that battle, I searched amongst the slain. To the last body. My father was not among the dead."
81,8 sec (= 1:22 min)
03:31-03:38 / 04:53-05:27
In the Theatrical Edition (=TE) Gandalf is visible half a second longer; then, Thorin's reply is shown in an alternative take. He says the same text, "He still lives, I am sure of it!", but in the Extended Edition (=EE) he sounds more determined. Then, in the TE we see Gandalf in a closeup, as the waitress brings him his mug. In the Extended Edition there is some more dialogue instead.
Gandalf: "The ring your grandfather wore, one of the seven given the Dwarf-lords many years ago, what became of it?"
Thorin: "He gave it to my father before they went into battle."
Gandalf: "So Thrain was wearing it when he... When he went missing."
Extended Edition 27,2 sec longer
Theatrical Edition is longer
14:06-14:20 / 15:55
After Beorn has turned into a human, there is a small scene with Bilbo which was removed from the Extended Edition: he is lying in the house and sees Beorn enter.
+ 14,7 sec
14:25 / 16:00-16:04
Another shot of the idyllic landscape and some wood chopping.
14:37 / 16:15-16:16
The bee comes in from farther to the right.
14:38-14:47 / 16:17-16:26
The rest of the shot where Bilbo is coming forth is basically the same. However, there are different things happening in the background. In the TE we see the whole group of dwarves sitting around the table. In the EE there is a longer additional scene (see its description right after this), therefore we see the dwarves standing together and walking out to the right.
No time difference
14:47 / 16:26-20:56
More wood chopping and some discussion among the dwarves. Gandalf tries to comfort them; the dwarves discuss the possibility of fleeing from Beorn. Gandalf is reluctant as well; however, he comes out and speaks with Beorn. He describes the situation of his companions who appear in small numbers. Beorn is not amused that all of them are dwarves. Then Thorin appears; Beorn looks as if he recognizes him.
Nori: "Well, I say we should leg it. Slip out the back way."
Dwalin: "I'm not running from anyone, beast or no."
Gandalf: "There is no point in arguing. We cannot pass through the Wilderland without Beorn's help. We'll be hunted down before we ever get to the forest. Ah, Bilbo. There you are. Now, this will require some delicate handling. We must tread very carefully. The last person to have startled him was torn to shreds. I will go first and... Uh, Bilbo? You come with me."
Bilbo: "Is this a good idea?"
Gandalf: "Yes. Now, the rest of you, you just wait here and don't come out until I give the signal."
Bofur: "Right. Wait for the signal."
Gandalf: "And no sudden moves or loud noises, and don't overcrowd him. And only come out in pairs. Right. No, actually, Bombur, um, you count as two so you should come out alone. Remember, wait for the signal."
Several dwarves: "The signal. Right."
Bofur: "What signal would that be?"
The other dwarves look as puzzled as he is.
Gandalf and Bilbo walk to Beorn, and Bilbo remarks: "You're nervous."
Gandalf is nervous, but hides it: "Nervous? What, nonsense."
Beorn is chopping wood, and Gandalf has to repeat several times: "Good morning. Good morning!"
Beorn: "Who are you?"
Gandalf: "I'm Gandalf. Gandalf the Grey."
Beorn: "Never heard of him."
Gandalf: "I'm a Wizard. Perhaps you've heard of my colleague Radagast the Brown. He resides in the southern borders of Mirkwood."
Beorn: "What do you want?"
Gandalf: "Well, simply to thank you for your hospitality. You may have noticed that we took refuge in your lodgings here last night."
Beorn looks at Bilbo: "Who is this little fellow?"
Gandalf: "Well, this would be Mr. Baggins from the Shire."
Beorn: "He's not a Dwarf, is he?"
Gandalf: "Why, no. No, he's a Hobbit. A good family and unimpeachable reputation."
Beorn: "A Halfling and a Wizard. How come you here?"
Gandalf: "Oh, well, the fact is that we've had a bad time of it from Goblins in the mountains."
Beorn: "What did you go near Goblins for? Stupid thing to do."
Gandalf: "You are absolutely right."