A DSLR is overkill for this person. The SX10IS has a 20x optical zoom lense and 4x digital zoom to help with those long mountain shots while hiking or biking. Plus it's all self contained - no need to buy extra telephoto or macro lenses.
Having been a professional photographer, I can tell you the best camera is the one you have with you and that you use. DSLR's require a lot of baggage.
JohnNJ
I will agree with you there. They require a lot of attention with their environment too, such as humidity and heat. Hiking and mountain climbing with an SLR is asking for bad news for the camera.