All the internet chatter today is about Steve Jobs’ big keynote speech at Macworld.

And one of the new products is the ultra-thin MacBook Air. But why is this on Greenthinkers? Well, other than the fact that we love our Macs, the MacBook Air is a step in Apple’s continuing environmental improvement. With its aluminum enclosure, Apple’s first mercury-free LCD display with arsenic-free glass; and brominated flame retardant-free material for the majority of circuit boards as well as PVC-free internal cables, the MacBook Air is the most green of Apple’s line.

But, as a note, it doesn’t have a user-replaceable battery - it has a sealed, non-user-replaceable battery like the iPhone. Odd.

And as the press release notes, the Air also consumes the least amount of power of any Mac, and its retail box, made primarily from 100% post-consumer recycled material, is 56% smaller by volume than the previously smallest MacBook packaging.

More to come as details trickle out.