I'm a bit late with this one but those crafty guys at Kotaku have been snooping on Pandemic staff and their personal blogs to suss out some Dark Knight media, and it looks like they have scored some success.
Michael Pryor, 3D environment artist at Pandemic Studios Brisbane, had some really great looking screen shots of what we can safely assume are from the Dark Knight game. It probably hasn't helped that Michael has pulled down those shots from his blog, but Kotaku saved some smaller versions of it and hosted it on their site. It looks absolutely outstanding.
http://www.kotaku.com.au/games/2009/01/rumour_is_this_pandemics_dark_kn…
His blog is at: http://michaelpryor.weebly.com
Travis Ramsdale also pulled down two Dark Knight related animations from his personal blog, but that hasn't stopped Kotaku grabbing it on hosting it on their site either as you can check out two animations from the four-year Pandemic animator. Travis described himself as "recently spent two years working on an unreleased next generation, open world title and responsible for animating the core movement set on the games hero character" and seems to have flown to Germany to look for work.
http://www.kotaku.com.au/games/2009/01/want_to_take_a_real_quick_look_a…
Travis's blog is at:
http://travisramsdale.blogspot.com
http://www.travisramsdale.com/index.htm