Doom is not dead... but the source is free.
Doom got ported to GBA... and seems to run well. Its official and being sold in stores.
Halflife and its offspring run on what is really a modified version of the Quake1 engine. And the Quake engine source is open.
If the Duke 3d source was open... it would bring new life to an otherwise dieing game. We'd see GLDuke and probibly DukeDC... eventually maybe even PS2 and X-Box Duke... The thing is to use any of these you would need a copy of Duke 3d for PC. And well... You'd have to find a place to buy it
3d realms would make a little extra money off of a very old game!
But this thing about 3d realms loosing the source has been said for YEARS. Its even on their website... (last I checked) They said it not too long after the Doom engine source was made public because many people looked to them hoping they would follow suit. Wether its true or not I have no idea...
Its odd that they would loose the source to such a commonly used (for its time) engine. Its also odd that they would lie to the public (and the fans) for so long about it if they didnt really loose it.