Well nobody replied, but I bought one anyway.
The Sony Cybershot P100, using the Sony Housing, works very well underwater. This is a small BC pocketable device, with the option for a URPro color correction filters. The focus and shutter lag is very low, and the camera and housing as they stand will take absolutely beautiful nearfield (4' to 4")pictures, even using the on board strobe.
As the field moves out to (4' to 20') in cold green Pacific waters, you need a strong strobe, or as I have done, adapt my video light bar. The camera does not have much exposure latitude, but with adequate lighting it takes a fine photo.
The battery has more than sufficient power to run thru a days shooting and then some. With a 1GB memeory stick there is plenty of photo room. The movie mode is nearly useless unless you are in crystal clear well light waters, but then it does have some fun aspects, thou it cannot replace a good video cam.
I especially enjoy the focus feedback as compared to the previous Cybershot cameras. This is a nice easy to use snapshot package, much better than the more bulky equivalents