Well I originaly wanted to just walk the entire length now after doing a couple sections last year i would really like to compile a photo journal with some of the better shots used for large format prints/art suitable for framing(rebel would be better?).
Based on this additional information, I'm going to revise and extend my remarks. Here are some thoughts, in no particular order:
1. At a hiker gathering last year, I watched a terrific digital slide show of a CDT thru-hike by a couple who obviously spent a lot of time and energy on photography during the hike. They used multiple compact cameras, tripods, carried a lot of cards and batteries, etc. Photography was one of the primary purposes of their trip, and their show was terrific (if a little long.)
2. Out of about 2000 pictures in the show, they had exactly one shot from a rainy day. They just didn't shoot in bad weather. Perhaps a waterproof compact like the Pentax WP series might be a good addition to the camera gear.
3. If you take an SLR, you'll need to clean the sensor. Even if you never change lenses, it'll get dirty under hiking conditions. Compact cameras don't require this.
4. Carrying several cameras, perhaps a long-range compact zoom and a wide angle zoom, would be a decent way to cover a wide lens range with lighter weight and less bulk. Something like a Nilon 8400 (24-85mm~e) and a Canon S5 (35-430mm~e), that sort of thing.
5. A Digital SLR with a lens or two would, of course, provide better image quality, more control, quicker response, etc. It's feasible -- I have done multi-day trips with two professional bodies slung over my shoulders with big honkin' zoom lenses and extra batteries/lenses/flash in my pack. But that was strictly work-related. A D-Rebel and an 18-200 zoom would be light enough to carry over one shoulder, always ready.
6. My personal reaction to photography and hiking is very much tempered by the fact that I work as a professional photographer. I hike to get away from work, not add to it.
Good luck and happy trails.