Ocean Rift, one of the most popular demos for the DK1, has been updated for the DK2. Watch as I explore the ocean floor, encounter various underwater creatures, and possibly get eaten by a megalodon. Ah, who am I kidding; we both know that's why you're here. You can watch me die at the 8:47 and 22:47 marks, though I recommend turning down your volume for that last one.
Ocean Rift is made by Llyr ap Cenydd. You can download it here.
Here are the impressions I wrote on NeoGAF:
I tried out Ocean Rift for the first time yesterday. It's been updated for the DK2. I never played the DK1 version, but I heard enough about it to know that it was one of the more popular demos available. It's a pretty peaceful experience as you explore the ocean floor and see what underwater creatures are out there. There are also preview screens of the final game (releasing when the consumer version of the Oculus Rift does) hidden throughout that you can find. Someone on here mentioned how it feels a bit more realistic than other demos due the Rift kind of feeling like scuba goggles or something, and it's true. It's recommended you play the demo with a controller and headphones, though you can also use a mouse & keyboard if you want.
And, of course, venturing out into the deep is not the best idea. This is hinted at on the info screen in the beginning, but I can say that it is indeed scary. I think that may be the loudest I have screamed "Ah, fuck!" while playing a game. I'm not into horror games, so it's not often I get startled like that.