[smcl]

Someone wasn't around back in 2001 for Duke Nukem Forever's tantalizingly close-to-complete looking trailer: https://www.youtube.com/watch?v=TDlB2P1leRM

But jokes aside, this is probably much more than a little teaser and given that it is in good hands I'm sure you are correct that it's well on the way to completion :)

[smoldesu]

The game's troubled development is probably documented better than the Titanic by now, but FWIW there were a number of points in development where the final product was playable, but didn't get out to store shelves for one reason or another. A few leaks of those various builds actually surfaced recently, and a lot of people found pretty reasonable grounds for the game's development restarting. One of the alpha builds even used straight-up porn as a placeholder texture... I empathize with the project manager(s) of Duke Nukem Forever.

[bombcar]

Yeah, based on the Apr 1 announcement I assumed they were just beginning work on it, but it seems they had it well underway before revealing.

[soneca]

Yep, Ron said it was in development for some time before the April 1st announcement.