The amount of FUD in some of the comments... good grief. People are sad/whiny when Apple doesn't change things and they're sad/whiny when they do. Or maybe they're different groups... but I'm inclined to bet that there's significant overlap between both.
You generalize "change". People want Apple to "change" old models of Mac computers to introduce new technology that already exists in the PC arena..ie., to keep current, instead of selling 4 year old technology like the Mac Pro. The change here replaces something that no one really complains about, and doesn't offer any significant improvements, instead is just a different way of doing something that already works all in the name of what they think is the holy grail -- a full glass front.