I modded my waterproof housing for my Hero3 Black Edition. So that I could use the mic and a polarized filter. Heres the pictures and a link to the filter.
GoPro – Polar Pro Filters New! Cube Polarizer Filter-Hero3 - GoPro - Polar Pro Filters
One thing about the Hero3. You can play the video's from the camera to the tv. You got to see it on a 60" LED with surround sound.