The extra 2 GB of ram, backlit keyboard, and aluminum unibody arethe selling points.
I realize the MacBook has the plastic unibody, but do not kid yourself, apple is not starting with a solid block of plastic and milling it into a unibody. That is treatment is for only the aluminum models. The aluminum does not scratch with a fingernail and the base does not scuff when you set it down to use it.
The forged aluminum body is far superior to any laptop available IMO, but carbon fiber will be the next big thing.