Found some vids comparing the new Sony Action Cam to the GoPro Hero 2. Be warned they are a bit long and boring.Out of the water:http://www.youtube.com/watch?v=OvfXWzmldYI
The Sony is sharper has more even colour tones and the SteadyShot is a night and day difference compared to the GoPro. The lens flares a bit more but performs better in low light conditions. The high fps / slow motion function of the action cam is sweet but you can't record sound at the same time.Underwater:http://www.youtube.com/watch?v=y9jOumi-53k&list=UUSt7Sc77Cs-nGxp0BsFTFHA&index=9&feature=plcp
The guy uses a modified Contour case as there isn't an OEM flat lens kit for the Sony yet. Under the water the Sony is no good as it has an inbuilt Auto White Balance (AWB) filter which adds extra Cyan. This makes the sky more blue outside the water and everything blue in the water. Which can look ok when you're up in the tropics but not so good in the limited vis stuff round 'ere.
I'm keen on the Sony as I like having the lens on the side like the Contour rather than the front like the GoPro. But the AWB issue and no flat lens dive case (as yet) means I'll wait until there is a firmware fix for the AWB and a flat lens dive case. The GoPro 3 is just around the corner as well which will make it interesting as it is smaller and lighter than the current generation.