lenscoat web site seems to say that those coats are to protect the camera while temporarily stowed -- look like a glove for the body with the lens poking out.
Not sure this would be useful for a wedding photgrapher -- don't you need to have the camera available fairly quickly in those places? This coat looks like an interesting variation on the classic "never-ready" case, cause of fumbling and anger when you need the camera quickly.
What's the big hazard to your gear shooting a wedding -- spraying champaigne? Tossed flowers?