Loren, the DSLR is NOT about to become obsolete and neither is the advanced consumer point and shoot. Both work great for fly fishing pix but the key to getting high-quality fly fishing pix is the quality of your camera lens, your preparation and photography techniques.
I first began photographing trout behavior 7 years ago, using a Panasonic DMC-FZ10 IS 4MP advanced consumer megazoom camera. It was the first telephoto megazoom on the market that had image stabilization. It had a very fast Leica f2.8 built-in lens, with the f 2.8 aperture running throughout the entire 24-420mm focal length of the zoom. And you need a very fast, variable length telephoto lens if you want to be able to capture high-quality trout behavior pix. I've gotten several photos published over the years using that camera but I've yet to see any recent advanced consumer mega-zoom cameras that have an f2.8 aperture that runs the entire focal length of the zoom. And, like you said, most publishers now want either RAW or TIFF photo submissions. So, a few years ago I went to a quality DSLR, a 100-400mm zoom lens (trout behavior) and a 100mm macro lens (trout flies). Trout and trout flies are two of my favorite subjects...I've been an avid fly fisher and wildlife photographer for several years.
Actually, any decent entry level DSLR camera will work for photographing trout but it's the lens that's going to make the difference. You've got to use a quality, fast zoom lens that has image stabilization. The focal range of the telephoto zoom should go from a wide angle at the short end to at least 400mm at the long end so you can catch the action from the strike out in the riffles, then as the fish is being reeled in, to the close-ups when the fish is at hand, along with shots of the release. But my camera/lens set up is about 7 pounds, which leads into my second point.
To achieve quality DSLR captures, you'll need an excellent fisherman to help you. I bring along my hubby. He's a superb fly fisherman and knows exactly where to lead the trout so I can get my best shots. I'll bring my rod along and wet a line but when he gets a fish eyeballing his fly, that's when I put my rod down and grab my camera. To get the kind of pix that publishers want, you need a partner who knows how to play the fish and where to lead it so you can capture interesting shots of the fish at different focal lengths, from different angles and perspectives. The days of "the guy holding up the fish" are over for most publishers, who now want intriguing, spectacular trout behavior pix.
If you intend to shoot in raw, there are also some other things you need to think about. Raw image files are incredibly huge so you're going to need a big computer with a fast processor to be able to store and process all your raw images and an external drive for backups. You'll also need a conversion program to convert the raw images to tiff or jpeg files in order to edit them in post processing. You didn't mention whether or not you were editing your images but most publishers have specs for photo submissions which include their desired file format, the resolution (usually 300dpi) and whether or not they'll accept any enhancement or modification of the image. You'll also need to buy more memory cards for your camera since you won't get any where near the number of raw images as you would with jpegs. Shooting pix in the Raw file format doesn't come cheap. You'll need to allow more time for photo-editing, you'll need the right equipment and you'll also need more memory cards or at least higher capacity cards, which aren't cheap. Bottom line, you need a full piggy bank to subsidize this format at the front end. Now for my last point.
I don't think that I've taken a pic of a trout from a standing position in over 5 years. I've found that when photographing most wildlife, including trout, my best shots are taken from either a low or ground position, which makes the shots more intimate in nature...with readers seeing the fish at eye level through your eyes. When I start each shoot, I kneel down on one or both of my knees in the water to capture the trout rising to the fly and its first wild movements right after the strike. These shots are usually taken almost at water level, at the max. focal length of the camera lens. Then, my hubby slowly leads the fish toward me at an angle into the slower water, so I can take shots of the fish from different angles, heights and perspectives. As this is happening, I tighten up on the shots, moving in on the zoom lens. As the fish gets close to shore, then I lie spread eagle on the bank or river rocks so I'm at eye level with the trout. I take pix in burst mode until the fish is at hand. But I don't stop there. Some of my best shots come at the moment when the fish is released.
To be perfectly honest, I've found that photographing trout behavior is far more difficult than photographing large animals (ie: bears) because trout are constantly moving at high speed. Kudos to you, Loren, for putting a new challenge into one of your favorite past times! I hope that some of my suggestions will help you and, BTW, tight lines!