Well I suppose I'll add my two cents.
I like to hike light; and climb lighter. This doesn't prevent me from carrying a dslr kit, though. I feel that getting a good image is paramount, especially in remote, unusual, places.
When simply backpacking, my pack starts out pretty light (20-25lbs). In this case, I'm willing to take a fairly large kit (for me). I bring one body (20d), both of my F4 zooms (17-40, 70-200), a tripod, and cards and the like. I do not bring a camera bag, I just got one of those little neoprene covers and stuff everything in the top of the pack, (for easy access). I may add things such as a fast prime, but only if I anticipate a use for it.
On alpine climbs, the pack gets heavier and the work gets harder. After adding a rope, rack, crampons and ice tools, I don't have as much room for heavy gear. I almost always ditch the tripod. The tripod is heavy and there won't be any time to use it. I may also drop the long zoom. Simply carrying the body and lens in the top of the pack is worth the effort.
When planning a trip, consider what photographic opportunities you'll have. You'll probably want the wide lens; but do you need something longer? Will you be awake and shooting a dusk/dawn? If so, you'll definitely need the tripod. Consider dropping other luxuries in exchange for photo equipment. Do you really need a stove, a pillow, a full-length mat, and so on.
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This photo was taken a few weeks ago on Warren Peak, MT. Difficult conditions for a DSLR kit. Long showshoeing approach, bad weather (the camera body was crusted in ice and snow), and cold temperatures. I brought only the 17-40 mounted to the 20d; I knew I wouldn't have time to use anything else. I took few photos, but was really happy with the ones I got.