There is not much left to say about the Twilight-franchise. Pretty much everyone should know the series, whether they like it or not. Lionsgate had an idea for those, who like the story about Edward Cullen and Bella Swan: A triple feature box set including the first three movies in an extended version.

Eclipse includes five minutes of new scenes which again solely revolve around additions to the plot, which might be nice to have for fans. Some of the sequences are deleted scenes that simply were cut back into the flick. The movie does not get any better or worse through this alteration. So far, the extended edition is solely available in the USA.

This is a comparison between the Theatrical Version and the Extended Edition, both released by Summit/Lionsgate.

There are 9 differences:
5 additional scenes/shots in the Extended Edition
4 scenes with alternative/additional footage

The Extended Edition is 284.66 seconds (~ 4:45 minutes) longer than the theatrical version.

8:46 minutes
After Bella left the car, the Extended Edition includes another scene of her and Edward at the front door. Edward says that he wants her to be happy and that he understands if she is mad at him and if she would not want him to come into her room later on. Then follows a cut and we can see Bella closing the window. After hesitating for a moment, she opens it again.
31.11 sec.

28:52 minutes / 28:20 minutes
The confrontation of Edward and Jacob infront of Bella's house was extended. For this, they used some alternative footage. Bella tries to calm the tow of them down, since they have the same goals, however, it does not work.
27.53 sec. / 9.84 sec.

Extended Edition	Theatrical Version

29:24 minutes
Bella asks Jacob and Edward to at least try to work together.
15.72 sec.

30:11 minutes
A longer dialog between Bella and Angela. The latter realies, that there is something wrong with Bella and thus asks her about it. At first, Bella does not want to talk, then she starts. Of course, it is about Edward and Jacob.
114.45 sec.

39:32 minutes / 36:33 minutes
The crisis meeting because of the New Borns was extended. Bella wants them to start negotiating now. However, Jasper and Carslile do not want this because they have some concerns.
40.67 sec. / 10.97 sec.

Extended Edition	Theatrical Version

48:21 minutes / 44:53 minutes
The shot of Bella is different in both versions due to the additional scene. Rosalie says that she would have loved to have a baby. The following shot of Royce and her starts a little earlier in the Theatrical Version.
12.14 sec. / 3.05 sec.

Extended Edition	Theatrical Version

52:27 minutes
Riley's speech was extended.
17.56 sec.

55:20 minutes
Charlie and his daughter walk along the path with arms linked. He is proud of her and says that she is his biggest accomplishment. Of course, Bella does not believe him.
28.45 sec.

1:39:58 minutes / 1:35:34 minutes
Edward rebukes himself for leaving Bella back in the days, which lead to her starting to feel something for Jacob who took care of her. He wants her to be happy.
27.11 sec. / 6.22 sec.

Extended Edition	Theatrical Version