I have a MBP and a MB... I can honestly say... the back lit keyboard isn't worth it... it looks cool and people notice it. Makes for a good "neat! I want a Mac!"
I am a touch typist, I don't need to see the keyboard to type (oh, and don't forget people, the little nubs on J and F are for finding your "home").
When I was in school, our computer/typing class made us type with the room dimmed and a sheath over the keyboard... it forced us to learn how to be touch typist. (Wow, that really sounded like some kind of weird conditioning training thing)
But, I do understand the need for some people, my dad who uses computers every day, still doesn't touch type, and hunts and pecks a lot, so I know it would be good for him.... so I don't think its completely useless, just something that the new generations wouldn't need as much.