Gearbox boss Randy Pitchford touched on the future of the Duke Nukem franchise in his keynote address at Develop: Brighton, which IGN wrote up in this report. While saying "I liked that game" about Duke Nukem Forever, he admits they did not acquire the IP just to release the overdue shooter, though the plans for the series he outlines at this time don't sound very concrete. Randy says they've played around with a couple of concepts, though it sounds like want another developer to flesh this out (maybe 3D Realms is available?). He also states that "getting attention is one of the hardest things to do," though Duke Nukem Forever project managed to get more than its share of attention for 12 years. Word is:

"We’ve done some concept development [for a new game] and I think the challenges are there. Gearbox is very busy. I think the faster way is that a correct developer can become interested and we can work with them. I think it’s a challenging problem. But, I’ll tell you one thing. When it does happen, there’s no doubt that the whole industry will turn its head and look.

"Getting attention is one of the hardest things to do. In fact, that’s probably the biggest challenge that [Duke Nukem] Forever had. For 10 years, these guys promised that it was going to be the greatest game ever right? It was legendary in its vapourware status. So it has this particular pole of attention that makes it probably three or four times more famous than Borderlands as a franchise. Not necessarily from a gamer's [perspective] that are really clued in to what’s going on in game development in the industry, but certainly among the greater whole community."