Oddly enough, I've been down this road before. I ordereed a Blackberry Pearl on launch day almost three years ago. It was and still is the ONLY Blackberry to ever provide colored LED's under the trackball. Just like Google, they put them in there and never really used them. We never did get RIM to activate them although they did give developers the ability to activate them.
RIM never did add the colored LED's to any other Blackberry device either, not even subsequent Pearl devices. It seems as if it was an idea they had and then abandoned right before launch.
Hopefully Google will use the colored LED's in more ways than they currently do, and if not, give developers the ability to use them.
RIM didn't continue putting multi-color trackball lighting in other devices, but they did start making the notification light multi-colored. Of course, now RIM has basically moved on from the trackball all together, so in that case, it really makes sense that they just stuck with multi-color notification lights on newer products. Of course, you still need to get a third-party app to implement different color notifications, but they're out there.
For me, I figured out a long time ago that it really didn't matter what color the notification light was blinking on my BB, I still check it as soon as I get the chance.
I'm glad to know that Android handsets offer some form of notification light feature, because it is quite addictive. When I finally make the switch to Android (sometime this year), I'll really miss the BB Messenger, though Gtalk and Google Calendar shared calendars should replace all of the functionality I got from BBM. The only thing left to miss will be the auto-standby holstering, which is a nice thing, but I think I can survive without it.
-SR-