Did it occur to anyone that maybe these UI changes are not coming until OS 11?
No one said these changes would be monumental. The claims of Apple switching to a "black" or even "darker" UI are unwarranted. One might deduce that from a name like "Illuminous" that were would be a shift towards light, or glowing.
Plus, you never know. Just as system 7.5 was a SIGNIFICANT upgrade from system 7, 10.5 might also be a major turning point in the life of OS X. However, just like 7.5, there might not be a complete rebuild of the OS until "OS 11." The point is, we don't really know how Apple is regarding Leopard. Is it just another OS X? Is it monumental enough to make changes to the UI?
My guess is that there is added heat due to a coinciding Windows release (and one that is so intently bent on "catching up to OS X"), Apple will do everything they can to put the current OS X behind them.
And when you think about OS X, it has truly been a work in progress. From the barely usable puma to a finally working Jaguar to a mature Panther and a refined Tiger, Apple should finally be at a point where they're ready to take everything they've learned and release a truly polished and exquisite OS.
-Clive