When someone works for over ten years on the same project, well their portfolio tends to not have a lot in it. With all of 3D Realms let go with the studio's closure, there are plenty of artists looking for a job now, and most of them have a portfolio filled with Duke Nukem Forever goodies.
Joystiq got their hands on concept renders from artist Chris Smith, and there's plenty of goodies here from vehicles to characters.
Brian Brewer took matters into his own hands and uploaded a video to Gametrailers.com showing not only game models, but actual gameplay footage. Can you say stadium level?
Video NSFW
It really is a shame that this project actually died. The video footage actually looks pretty compelling. *NOTE* - There is one stripper shot in the video, so NSFW.
Lets hope Take 2, who owns the IP now, can shop it around to another developer to finally finish it up.
The 3D Realms website has closed shop and they posted a farewell pic of the development team there. Lets hope these folks land on there feet somewhere, and end up making some great cooperative games!