I highly recommmend the Casio Exilim EX-Z750 (or the new 850) as a backpacking camera.
I guide small group hikes, and document it all with stills and short videos using this camera. With a little care, and understanding of the three-color(!) histogram, I can get great results. In difficult situations such as low light, backlit, night-video, multiple shots, etc.. pre-programed or custom setups are available within a few button pushes. I have owned 6 digi-cams, and for so many reasons, this one is the best overall. For the beginner, it is a great point and shoot camera, for the professional, it has amazingly advanced features. As a beginner, I have learned a lot about photography simply by learning the features of this camera one by one.
This review from a professional photographer was key in my decision to purchase: http://www.kenrockwell.com/casio/exz750.htm
I have enjoyed positive feedback from so many fellow-hikers, thanks to the images I captured using this camera. Short videos of the group are especially entertaining to my friends.
Like Mr. Rockwell, the reviewer, I always keep it with me.
When hiking, I carry a mini-pod (available in the BPL gear shop), a wide angle lens the size of an oreo, and in really wet situations, a Pelican 1010 case. My camera has been submerged, had the lens barrel choked with sand, dropped and abused, and exposed to extreme heat and cold. If it were to stop working, I would buy another the next day.
If you want to wait for the perfect backpacking camera, do so; but in the mean time get an 850, or a great deal on the old 750 and start documenting your adventures.
Incidently, I sometimes carry a Panasonic FX-01 for WXGA video or 8MP stills at 28mm, but even that expensive FX-01 with its Leica lens can not match the low light capabilities of my 750.