I am partial to Canon and am excited to see they are introducing a model in the rugged, waterproof class. I previously used the first generation waterproof Olympus Stylus and after it broke moved to the Pentax Optio W series. It has been a good camera as far as durability, but it just doesn't produce photos like our Canon Powershot SD1000.
As far as the post question, I can't wait to see some product reviews/comparisons. Based on my previous experience with the Stylus line, I am ruling out the Olympus. Although right now I am leaning towards the Canon based on previous experience with their products and superior photos. However, the Panasonic offering higher video quality in HD format is enticing.
I've owned the canon SD870 IS and enjoyed the quality of the pictures taken by it. Though, unfortunately it is not shockedproof that when my 15 month old son accidentally dropped it - there goes the camera. Thus, I am planning to get a camera that can take on some of the challenges parents have while capturing life moments - swimming in the waterpark or pool, playing in the snow or the accidental drops. :)
Having a rugged camera is not enough - I would still want to capture good quality pictures that I could frame.
Having owned the canon SD870IS - I too prefer the Canon D10. However, from what I've read on the Canon D10 it is not pocket size when compared with the other two.
I really like the HD video capture by Panasonic DMC-TS1 and was disappointed to learn that the Canon D10 does not include this feature.
I almost removed the Olympus from my list based on card requirement. You need to use xD card to get all the functionality listed (yes - the SD card on the 8000 has limitations)
Agreed re: xD killing Olympus sales. I won't buy another Olympus until they drop that format. On the other hand, you are incorrect in your statement re: compact flash. It is not a "special media type"; it is used by many dSLRs, including Canon and Nikon. Further, Canon did not drop CF cards in the EOS line. They only dropped it in the entry level Rebel dSLRs. The xxD and higher lines still use CF cards as they are preferred by many working professionals.
The Olympus Tough-8000 also takes micro-SD cards with the included adapter. Which takes away that disadvantage for me, since I have some of these. The disadvantage to me with the Olympus is the smaller max aperature, and the contrast-detection AF. This means slow, potentially motion-blurred (or high ISO = noise) images. Advantages are size and wider wide-angle (28mm compared to 35mm - significant, especially underwater). Also the shutter speed has limitiations with the max time topping out at 1/4 second - not fun when you actually have a tripod and want to do something artistic at night. It says under night mode you can stretch it to 4s but there are always compromises in scene modes (high ISO probably for this one)
The Canon D10 provides TTL AF, Max aperature of 2.8, but it is larger and the big disadvantage is the focal length starts at 35mm - not necessarily a big deal except underwater. Water has a higher refractive index than air which makes focal lengths longer for photos taken underwater.
The Panasonic seems to be a blend of the two, offering TTL Autofocus (faster) and shutter performance improvements on the Olympus (I care more about the long exposures, and Panasonic is the best of the three with 60 seconds), while widening the zoom range to 28-128mm equivalent (widest of the three). Max aperature is f/3.3 which is slightly better than Olympus and worse than Canon, but it stays thin like the Olympus and has HD video which might make the deal for some.
I don't have any of these and image quality will be a major factor as well. I feel the Canon will be the best because it is straight-through optics but it isn't out yet so no one knows. I think by writing this I have convinced myself to buy the Panasonic. AF, wide angle, and size are critical to me and while I hate to give up f2.8 at the wide end the size and 35mm max of the Canon is too limiting. I have my Nikon DSLR for IQ so I want something small which can go everywhere. HD Vid just adds more joy to my decision!
I bought the Panasonic DMC-TS1 after reading great reviews. I also liked that it had better (HD) movie options and a wide angle lens than the Canon D10 and was smaller and lighter...
For what it's worth, I returned it after two weeks. Despite the reviews, the picture quality was terrible compared to my Canon SD700is. I didn't even try underwater because it failed in normal conditions (indoor, outdoor, daylight, night, etc.). The macro mode was nice and the movies were great actually, but the pictures were substantially inferior to the 3 year-old 6 MP Canon. Also, you have to send the camera into Panasonic every year and pay $140+parts+tax+2-way-shipping to get the seal replaced to maintain the waterproof feature. You can skip this, but at your own risk and likely voiding any extended warranty. That's too high a cost-of-ownership for a small p&s camera that will be taking out-of-water pictures 95% of the time...