I Followed this game for sometimes and was disappointed when it was dropped although admittedly I felt that with every little crumb of info of shots wasn't looking all that much better than the last. Seeing the Video here it looks like Duke Nukem Forever, but id take it with a pinch of salt not to mention considering the work of 15 Years what that shows and what ive seen in other video's most other lower manned studio's could have pushed out the same in 2 years.
The Duke has never been the same since the Success of Duke Nukem 3D and while I've actually sat and played most of the admitted mediocre Titles following ive found them just passable (Manhattan Project) to trash (Land of the Babes anyone?).
Unless this game IF its trailer is legit as something stellar up its sleeve and they was only showing generic stuff in the trailer to keep all the good bits for us to find when / if we play it, I'm sorry its not going to stand out against the likes of Bad Company 2, Modern Warfare 2 and the likes.
As for do I think the trailer is legit, its hard for me to say. The footage while looking mediocre at best looks legit enough as ive seen just about every video about it when I was actively following its progress, the titles part doesn't seem pro enough to me, there's just something about it that I cant put my finger on that makes me wonder.
Time will tell my friends.