I've posted a sample video from a blue-water dive further down. The underwater video is best taken with a wide-angle lens, using a larger depth of field (if you have enough of light) to get the entire image in focus. Although they claim the camera can auto-focus while taking video, don't expect it to be very useable, especially underwater - it is a little clunky. Having the option for video underwater is really nice. I highly recommed turning auto-ISO off when using strobes. A very nice feature! The values are set in the shooting menu, and it is pretty self explanatory.
The ISO will automatically be adjusted, if a certain minimum shutter speed is not reached, up to a max ISO that you set. The Nikon D7000, like other Nikon models, has an amazing auto ISO function - which is great when shooting ambient light. The base ISO on this camera is ISO 100, which is a change from the ISO 200 base that the D300 & D300s had. DPReview says in their review that the D7000 may have the best high ISO performance of any current APS-C dSLR. I hardly notice any noise at ISO 3200 if the image is properly exposed, which is quite remarkable. The ISO on this camera goes up to ISO 25,600. Having a fast sync speed is nice when you are shooting into the sun, to help you gain a little bit more control over all that ambient light and not blow-out the photo. The max sync speed remains the same as the D300 at 1/320th, the best of any current dSLR out there. More is definitely better, I like to move my single focus point around. In changing from the Nikon D300 to the D7000, I lost some focusing points, I only have 39 instead of the 51 on my D300. The Nikon D7000 has more megapixels than any other Nikon dSLR except for the D3x, not a bad thing. Subject selection, composition, and lighting will still make the different between a good shot and a great shot. Still, if you are just displaying photos online, I think you will be hard pressed to notice differences between a new dSLR and a body a few years old. The new 16 megapixel sensor was great, and I noticed even more detail in my macro photos. I also like the dual-card slots, although compact flash cards are considered superior to the SD slots the D7000 has. To start off with - the battery life is amazing, even with using the internal flash to fire the strobes, the battery lasts at least a couple of days of 4 dives a day.
Of course, now the Nikon D7100 has just come out, which I'll probably upgrade to.
If you want to get top-notch underwater photos, seriously consider the Nikon D7000.
The ergonomics top-side are great, the body is fairly light, and it has incredible high-ISO performance, great dynamic range and great colors.