Duke Nukem Forever leaked gameplay video?

The embedded video seems to be gameplay of the famed vaporware 'Duke Nukem Forever'. It's a shame this game may never see the light of day, as it looks to be an entertaining mix of a first person shooter with adult themed antics (including the section where Duke investigates a gentlemen's club). With imaginative level designs, fluidly animated enemies, huge bosses, and at least one on-rail section, where you ride in a mining cart, it looks like the gameplay would have been both entertaining and fairly immersive.

There's also a forum thread with images of various Duke Nukem Forever assets, see it here