DSLR Video is a fast-growing new field in the filmmaking world. As manufacturers like Sony, Canon, and Panasonic release new cameras the field broadens more and more to include everyone from professionals like Philip Bloom to the kid next door shooting YouTube Videos. With all the cameras out there it's difficult to know which ones are right for your needs. For example, if you're looking to make videos of your kid's birthday party, you don't need to spend $3000 on a camera, but if you're wanting to start a business and shoot weddings or corporate video, you need to get the best camera you can. So, how do you know what to do? Here are a few guiding principles:
If you're just going to be using this camera for home video, you're better off getting something like a Canon T2i or a Panasonic G2. These cameras are less than $1000 with a decent lens and will do a more than adequate job of capturing all the great moments your family will want to remember.
However, if you're trying to start a video production business, you need to shoot a little higher. The T2i might work for you, but really, you need to be looking at a Canon 7d at the least. It's magnesium alloy body will hold up to the rigors of professional filmmaking and it's picture quality is amazing. If you're able to afford it, the Canon 5d Mark ii is the mother of all DSLR's. It's full frame sensor (same size as 35mm film) gives it picture quality that is second to none in the DSLR world. It's been used on big studio feature films and major network television productions and the image quality holds up extremely well.
As an exception to the thoughts noted about, you might want to consider a Panasonic Lumix DMC-GH2. It's a new micro 4/3 camera released by Panasonic a few months ago. While its sensor is much smaller than the Canon cameras, which is generally perceived as a negative, it makes up for that shortcoming with some innovative features that Canon has yet to employ. In addition it opens the world to a variety of lenses that no full-frame sensor could use. With the GH2 and it's predecessor the GH1, the filmmaker is able to use vintage 16mm film camera lenses with a simple, inexpensive adapter. In this way, you can buy amazing lenses used for a fraction of the price of Canon glass and get off the charts image quality. In addition it's a lot of fun to find interesting old lenses and see the results you can get from them.
In short, there's a lot of things to consider when looking for DSLR Video gear. But if you take your time and do your research, you can get a camera that will fit your budget and shoot amazing video fairly easily.