A member on the IMDB forums has posted what they say is going to be on the Order of the Phoenix DVD. Treat this as a rumour for now. The release date of the DVD is November 12.

Disc 1: Movie
* Optional Alternate Opening Sequence – the original snowy opening sequence
* Extended Finale – extended battle at the ministry of magic
* 20-Minute 3D Finale – the explosive finale in 3D format on DVD (and will include a pair of 3D glasses)
* Audio Commentary by the Director, the Producers and the Cast
Disc 2: Bonus Features
* 30 Minutes of Deleted Scenes
* Conversations with the Cast
* Reflections on the Fifth Film
* Creating the Fifth Film – a featurette about the making of the film
* Dolores Umbridge: Creating the Character – a featurette about creating the look of Professor Umbridge
* Meet Dumbledore’s Army and the Order of the Phoenix – a featurette about the members of the DA and the Order
* Voldemort and the Death Eaters – a featurette about creating the new look of Voldemort and the Death Eaters
* Creating the Creatures – a featurette about the creation of the Dementors, Kreacher, Thestrals and Grawp
* The Battle at the Ministry – a featurette about creating explosive battle at the ministy
* Self-Guided Tour of Number Twelve Grimauld Place and Umbridge’s Office
* Dumbledore’s Army Challenge
* Theatrical Trailers from All 5 Films
* Sneak Preview of the 6th Film: Harry Potter and the Half-Blood Prince
* PC CD-Rom Features
– Hogwarts Timeline
– EA Game Demo

Thanks Harry Potter Trio!