As far as i'm aware, even the weather sealed cameras and lenses don't really offer any guarantee against water ingress, more, that they are designed with an attempt to not making them soak it up like a piece of blotting paper. My canon 1ds with suitable lenses has been out in torrential rain and got great shots, and the trick is really to use a suitable lens hood and try and keep rain off the front lens element.
I've also shot film cameras in the rain, but try and keep to mechanical ones, as they will be less likely to be bothered by a bit of rain getting places that the designer wasn't thinking about (for example, i've taken lots of photos in the alps in winter out and about with a hasselblad).
So basically, if you want to be out in wet weather with a camera, take it in a bag that will keep the wet off of it, and have it out as little as possible, and you can use just about any camera. If you want to shoot a football match in the rain, a weather sealed camera is your friend.