theres always a case redesign, but its always minor, no ipod generation has ever been exactly same in terms of looks. They almost never update the UI though, technically the classic is the first time the UI has ever changed since the first ipod (not counting just adding color, which isnt really a UI change).
The classic isnt going to change much, it will probably get a better battery at most. They cant put in larger HDD's yet since there arent any they could use. The faceplate will get a small change while everything else remains the same.