This is my current project. I'm reworking the entire level like I did with D14. I don't plan to alter the monsters much, but the areas will be mostly new and include many tricks and traps to make your route to the Vile King less hospitable. The king is getting tired of so many folks intruding on his home turf. I also need to relieve some folks of their large bankrolls.
Keep in mind that D16 and the upcoming Dragon Lands and Area 51 (and one more extreme place I'm not naming) are supposed to be extremely difficult, even for the best players. A careful player should still be able to work their way (slowly) through these extreme places, but death should always be near at hand if you make a mistake. With that in mind, I'm open to suggestions to make it more interesting, but email them to me separately so it's a surprise for others.