I've owned a few PowerBooks over the years. I started out with a PowerBook 540c, and graduated over time to a bronze keyboard-equipped PowerBook G3 and three different PowerBook G4s. My third G4, a late-model 17-inch version, is now exhibiting the same trouble I've had with my last two: Keyboard rot.
I admit I'm tough on my 'Books. They're my daily drivers, after all: About 90 percent of the work I do is done on a laptop. Now, my past two PowerBook G4s were Titanium models, standard 15-inch systems. And both of them suffered the same problem: The lettering on the keyboard would rub off after a while. In fact, the keys themselves would get a glossy sheen to them that wasn't the result of hand oil or anything like that: It was an actual polish that would occur after I'd worn away the texture of the key. It was a precursor to a more serious problem, because usually at about that time that the keyboard itself would break. The scissor-style springs underneath the keys would eventually just give out.
Replacing keyboards on the old Titanium models is trivial. It takes all of about a minute or two if you have the replacement part in hand. I did it three times with my my other PowerBook G4s; after the last time, I began to feel like a well-trained soldier who could take apart his gun with his eyes closed.
So I got my new PowerBook late this spring, and I love it. This aluminum-clad 17-inch model is sleek, fast, powerful and big -- best laptop I've ever used. And the pretty keyboard lights up in dark rooms, too, and always impresses folks who haven't seen one before. But the aluminum-colored keys are starting to corrode again, and it looks unsightly.
It appears that the PowerBook's keys are colored on the surface, and I've worn away that colored surface coating, just as I'd worn away the coating on my older 'Books. The difference this time is that the letters on the keys are etched to let the light through, so the wear is even more noticeable. The A, S and N keys are showing similar levels of wear, and the E key is starting to show some wear as well. I don't know why this happens. I don't clean my PowerBook with anything caustic, and I don't rub it down with steel wool. I don't use sulfuric acid for a hand-wash, either.
The bigger problem comes in replacing the keyboard, however. This isn't a Do-It-Yourself project for the faint of heart: Getting the keyboard out of a new aluminum PowerBook involves a lot more disassembly than it did with the titanium models. Oh well.
After showing this to a few friends, one suggested that Apple should make the keys transparent and color them from the inside, rather than the surface, to prevent stuff like this from happening in the future. It's an interesting idea.