I do hope whatever form it takes they have a significant re-think for the line coming up. Apple's whole MacBook lineup is pretty boring from a consumer POV at the moment. The worst part is probably that you only really have a choice of two machines - an (expensive) 16 inch workstation, or a 13 inch thin and light. Yes you get a few more features and more power as you pay more with the latter, but there's no reason to be offering three hugely overlapping 13" machines to the exclusion of almost all else.
I recall seeing a rumor/leak about when we would see full case redesigns. Perhaps it was even Kuo who spoke about it. Does anyone have that link? Also, I wonder if the 16" is considered a case redesign. I would say no.