I'm not too fussed about the visuals, it could look like the original build engine, but what it really needed was a physics update.
Duke 3d as a game was fairly interactive for it's time, and with what they have to offer today, there's lots that could be done to take the epic legend, and make it an epic reality.
However visually speaking I am concerned that A) Textures are going to be similar to those seen in Unreal engine games. For whatever reason they are very plastic looking, and have terrible resolution at any close range/proximity. B) The shadows seem very last generation, with all of the mesh and ripping symptoms. This is probably partially a fault of GPU architecture as well. C) The other parts of it feel like something from the HL engine, which isn't inherently bad, but doesn't mix well with Unreal type engines.
I am still awaiting the day it's released, but given how long it's been, I do think 3D realms used it as a PR stunt. If they really wanted to see it released, they could have gone into partnership with someone else to help develop and publish the game, but they didn't, they just sat on the rights to the name.
Hell even Axl Rose finally released an album.