Had the farce of its development not abruptly dead-ended in May of last year, April 1, 2010 was to have been the date Duke Nukem Forever went to gold master - that is, was at last finished.
The detail was revealed over Twitter by former Take-Two Interactive producer Jason Bergman on April 1, so, naturally, a lot of people thought it was a hoax. Bergman in followup tweets vowed it was not, and that the team deliberately chose April Fool's day as the gold date - likely for the meltdown it would have caused in the gaming press.
(I don't even want to imagine being on shift for such a thing. First, it's this game. There would be enormous pressure on both sides: Not publishing, or going with it. Then throw in that it's April Fool's, and the people confirming the rumor have had, let's say, limited credibility on this subject in the past. Though to announce Duke Nukem Forever is on the way and have gaming news outlets deliberately not publish that is admittedly hilarious.)
The Cut Scene reached out to Bergman and was assured by Bergman the April 1, 2010 date was true. That would have meant we'd have finally had Duke Nukem Forever by late Spring or early Summer.