Canon has finally got into the simple point and shoot, waterproof and rugged camera market, normally dominated between Pentax and Olympus. I have never owned a Canon digicam but have seen the great quality of pictures from the various models. I have been very happy with my old Pentax W10 but I might upgrade to the D10.
After a year on the market, their seems to be a developing consensus that the D10 is at or near the top in the waterproof, shock resistant compact point and shoots. The most common criticisms relate to its size as it is significantly deeper through the lens than its competitors. It's definitely not going to disappear in a shirt pocket. In spite of that, it will still fit into a very compact case that can strap onto a waist belt for easy access.
Panasonic Lumix DMC-TS1 seems to be the top competitor that is better rated for compactness, video capability and zoom capability. Trade offs are less water resistance, more fiddly little buttons and poorer performance in low light settings.
It's a great little point and shoot. I got one with my air miles to use for snorkeling in Hawaii in March. I took it up to Whistler last week and was pretty happy with the photos. That and the fact that there was hardly anyone on the mountain!