The evolution of digital cameras has pretty much reached the point that there are no huge differences between the major manufacturers (Nikon, Canon, Sony, Pentax, Olympus) until you get into the higher $$ models. A good start is to go to a shop with knowledgeable sales staff and handle multiple cameras to see what fits your hand best and what features you like. Keep the features/limitations of your current camera in mind as you compare the new models.

A major camera company is best because of the availability of repairs should the camera being damaged at a scene. The better models of Canon and Nikon DSLR's will perform much better in low-light conditions due to their improved ISO range, which is a plus if you will be out working in the middle of the night.

I would not recommend a small point-and-shoot camera due to the image quality and camera capabilities. The smaller sensor (even though it's rated for 12 megapixels) of the compact camera will produce a lower quality image than the sensor on a DSLR rated for the same megapixels. Think of it like 110 film vs. 35mm film.

An additional advantage of a DSLR is the ability to change lenses as your needs change. Good quality lenses are an investment and will last for years longer than the body you buy today. Depending on your equipment, you may have older lenses that will still work quite well on a new digital body. (Sony can use older Minolta lenses, almost all Pentax and Nikon lenses should work on a new body but may not meter the exposure, and most Canon lenses will still work)

Please feel free to PM me if I can confuse the issue further.