The ad above states the following as extras on the August 2008 Blu-Ray release, as listed below.
-Creator’s Commentary on 3 Key Episodes
–Inside Justice League: Creators’ Panel Discussion
–Storyboards: The Blueprint of Justice
–The Look of the League: Character Design
–Justice League: The First Mission Never-Before-Seen Promo
–The Blackhawks Theme Music Video
Warner Home Video is expected to release a full press release, with the official rundown of bonus material, shortly.
Stay tuned for further updates.