Not sure why it would need to be smaller, the Cheesegrater was exactly what I'd expect a Pro level machine to look like and I've never been an apple user, I just love that case.
It's a pro level desktop, size (within reason) constraints aren't really an issue.
I agree. Bringing back the old design would immediately solve a lot of problems, but Apple won't do that. Even with a new redesign, I assume the system will still be designed to accommodate standard-sized GPUs and other add-in cards, unless Apple is going to use custom packaging, which is doubtful. That's why I guessed that they could potentially make the new Mac Pro smaller and have it sit on a desk instead of the floor, etc. Instead of the current cylindrical Mac Pro, it would go back to something box-shaped.
It's a pro level desktop, size (within reason) constraints aren't really an issue.