I don't know how you feel, but I was never crazy about traditional video and nature work. I had worked professionally with video back in the 1980s and early 1990s and did only a little nature work with some of the cameras I was working with. Standard definition video just did not do it for nature.
With HD, this has changed a lot. When we got our first HD television set, I was so excited to see wonderful nature presented in high definition. Nature finally looked good on video.
I started shooting nature with HD video with some camcorders a few years ago, but the cameras did not match the experience of shooting with a digital SLR. So when DSLRs came out with HD video built-in, I was very excited. These cameras offer three really great features for nature photographers interested in shooting video -- full interchangeable lenses, excellent wide-angle video, excellent macro capabilities, superb video quality and a small camera/lens package. None of those things were readily available with video camcorders.
This video was shot with the 7D, Canon 50mm macro, Canon 10-22mm wide-angle zoom, plus the use of a Canon 500D achromatic close up lens on the 10-22 for wide-angle close ups.
Audio can be a problem with DSLRs. Don't use the in-camera mic -- they are all pretty much worthless. I used a Sennheiser MKE-400 shotgun mic which I would not hesitate to recommend. I like it a lot. A friend had a Rhodes mike and I did not like the results as well as my Sennheiser.
This video really points out how cool video can be. Look at these bees -- brown against brown! Not very photogenic for the single image. But put these bees in motion with sound, and they literally come alive.