There are some nice, up-and-coming point-and-shoots available now from Sony, as well as some half-decent "mirrorless" interchangeable lens cameras, and the Canon s90/95/100/105 is still a damn decent little camera.
DSLRs just take photos with better image quality, though, and they get better battery life too. The balance is struck, IMO, with shorty lenses, and Canon has some damn decent ones. Usually, for scenery, 40mm is a good balance of wide angle without getting your feet in the frame, while still being appropriate for people shots, and close-range compositions. For a lot of trips, this is all I take. The coolest part is how small the DSLR becomes with half a lens on the front. The 28mm f/1.8 lens, I just got, but so far, I'm impressed. It's a great focal length for close-up wide angles like waterfalls or the inside of tents, and the f/1.8 will make it awesome for wide angle astrophotography.
That said, I do often miss having a telephoto when on the trail. The best lens for general outdoor activities would be a ~35-180mm zoom, like you'll find standard on some point-and-shoots but image quality suffers with superzooms. When I know I'm going to see cool wildlife, I might bring my 100-400mm telephoto lens (it's a zoom, but it's a good one, in the "L" class), but it adds a lot of weight (and concern for getting moisture in my gear) to my pack.
