I was just a little disappointed, but it would have been totally unexpected if the case changed.
I like the case, especially from a functional perspective (grate=airflow, size=expandability), the only problem is that it will be replaced or updated within a few years (nothing's guaranteed, but the case is what, 6 years old now?). This is only a problem because this type of computer tends to be owned for quite a while due to its cost and power, and when your computer looks old it's harder to sell and it's harder to keep one's self off the apple store looking for something new.
Perhaps i'm overly aesthetic (i suppose photographers are supposed to be, aren't they?), but when I'm considering something I tend to stare at that thing. Do i need a new car? well, i tend to think about it while sitting in it or looking at it...although i'm thinking of the pros and cons of putting a new clutch in a 14 year old car with 280,000 miles, i'm still looking at the thing, and i'm sure it has some (irrational) impact on my decisions.
All this said, the point is this: I will inevitably purchase the last generation of every apple product before it changes, so i'll let you know when I buy a new mac pro, and then you can count on change.