This was talked about previously as Gearbox got into a beef with one of the modders whose work was in the megaton edition. They wanted to re-negotiate his royalties and he basically told them to get bent, so Gearbox pulled the game and is replacing his work.
That's a rough cover of why it was pulled.
Moving on......Let's hope they allow or release themselves the Duke Nukem 3D-Reloaded game. It was basically made by the people who now own a majority state of 3drealms(I love that the company is still around).
Duke Nukem 3D: Reloaded was basically a HD remake of Duke Nukem 3D but with added levels and some new stuff mixed in with the classic levels and bosses and at the time was using Unreal Engine 3. The screenshots still look great and those that saw the game in motion were apparently blown away.
The story/lore goes that Gearbox loved it more than Duke Nukem Forever but with the obvious big investment they put into the IP to get DNF finished, told the fan project basically "yeah, you can develop and finish the game but we get ultimate say whether you can actually release the game" and well...Gearbox told them no. It's been sitting somewhere, pretty much a full game ready to go.
I miss Duke. My only complaints with DNF was that it was almost too sexual. Dial that back. Give us the Duke who loves and saves our chicks and kicks in alien scumbag's heads and I'm happy.
Always bet on Duke. Always.