Contrary opinion: I've been trying to jump from picture-taking to photography for years. (It seems that about once a year, someone stumbles on a picture of mine on Flickr and buys it to use it in a tourist brochure or something, so maybe I'm sort of a photographer.)
I know what to do with a DSLR, but I'd never pay the weight penalty to take one backpacking. They are just too darned heavy for the benefit that they give. I hike, and photograph, with a higher-end point&shoot (my current one is a Canon PowerShot SX150IS that I got on closeout). For a P&S, good optical zoom is much more important than megapixels. For super-high-resolution landscapes, the kind you can blow up and cover a whole wall with, I take a lot of individual frames and stitch them. I don't use the pano function in the camera for landscapes I care about. I use an open-source stitching program called Hugin, and tune the control points and exposure matches carefully. For the most part, the seams don't show.
Here's one from last weekend to show what stitching can do. (Click through and download the original size to see how it would enlarge.)
The big thing I miss with a DSLR is the ability to use filters. I would love to have a P&S on which I could put a haze filter (for better penetration on long range shots), a polarizer (for a more interesting sky), a neutral-density (for those waterfall shots), or an amber filter (for those stark Ansel Adams-style monochromes). The better glass that I'd get from interchangeable fixed-focus lenses would be a benefit mostly in low light, which isn't that often a problem Out There. (OK, it would also get me better definition in some shots, but most viewers don't notice...) A polarizer would have really helped add punch to the sky in that pic above. I would have taken off the haze filter because in that particular image I really liked the soft quality of the light.
I find having a macro focus capability is really useful, so you'd want to look for a camera that has one. More and more often, I find all the landscapes tend to look the same: mountains are basically piles of rocks, and one rock pile is very like another. But there's endless variety in the small things. On the same day as I took the landscape above, the Vernonia noveboracensis was in bloom, but without being able to macro-focus, I wouldn't have been able to photograph it properly.
Something lightweight that can serve as a tripod is also useful. One possibility is the TrailPix.
Photography is mostly about being where the shot is when the light is right. I've even sold the odd cell phone picture or two.
Sure, it's not what it could be technically, but the quality of the light was magical. And on that particular walk, a cell phone was what I had with me. I hadn't brought a camera. That moment of mysterious light wasn't going to last.