Whyever not? Bic hasn't changed its basic plastic ball point pen design in over 40 years. The Land Rover Defender has looked more or less identical for 61 years. Good products both of them, and nobody has ever seen fit to create a Defender made of carbon fibre that looks like a Bugatti and handles as if controlled by the Gods themselves.
However, I do agree. The MacBook will change. Things always change at Apple. Imagine if the iMac still looked like its G4 predecessor. Well no, bad example, that was the
best designed computer that has ever been and will ever be. But you get my point.
If anything, I think that Apple might toy with the idea of colours as they have done with the iPod Mini/Nano. At least I hope they bring back the BlackBook, since they have white
and black iPhones and the iPod (classic).
Failing that I can imagine in a few years time the MacBook will get the 12" PowerBook treatment and we will see the loss of the extra wide bezel and lip around the keyboard/palmrest. This will be echoed in the Pro/Air lines too. And possibly the iMac and 24" LED ACD will follow too in order to play the image across the lines.
Time will tell. Until then, we can all squabble. In the end, all we have are opinions.