In addition to the ones Otara mentioned, the new 16-35L is outstanding. If you are on a tighter budget the 17-40 L is hitting the used market in large numbers because folks are stepping up to the new lens. It's a real bargain now and works very well on the 7D. I have the 70-200 f4L IS version and have found it to be an amazing piece of glass that is always in my bag. It's a great boat lens for topside shooting. Not as heavy as the f2.8 version and much less expensive, many think it's sharper too.
Nauticam and others have come along way in their housing designs since the original 7D came out. I'm sure the new MK II housing when it makes its debut will be much better than the older one, but it sure would be nice to have the choice.
My wife will of course kill me if I house the 5D, because then I have to buy a new camera for surface photos.
Not sure I understand, why? The new vacuum systems changed my feeling on that. I'm much more comfortable putting a 5DIII with expensive lens in the ocean now. I haven't yet but I'm thinking about it. Of course we could still have problems but I'm feeling much better about not having to carry two bodies, etc.
By the way, I'm not getting into the brand conversation.
Looking forward to finding out. I see two small differences so far. The button to turn the mode dial like on the 5D MKIII would require setting the mode before you close up the housing. Not a deal breaker for me. And the new rotating switch around the joy stick , not sure what the function is.
Fingers crossed, how much fun would that new auto focus system be shooting macro!