I think he's obviously speculating. And I don't think it's puzzling. The MacBooks only received a minor update last revision.
The MacBook has had one design yes, but it is a continuation of the former iBook line, and the iBooks went from fruity and curvy to white and straight lines like the iMac. I don't think the idea that the iMac and the MacBooks more-or-less follow each other in design is a silly one. Even now, the new iMacs sport a keyboard design found originally on the MacBook, and on no other Mac.
The MacBooks followed the general iBook design, to the point where a MacBook and an iBook can be easily confused if seen from various angles. Of course, there were obvious changes also, but it's still the same general "white" (and now optionally black, but still the same) design we've seen with the iBooks since 2001.
I don't know if Apple will see fit to overhaul the MacBook's design, but I certainly hope we'll see some positive design changes in the MacBook soon.