Apple aired a new television ad here in the US earlier tonight. It touts the MacBook's low power consumption, recyclable enclosure and lack of some of the toxins present in other computers.
Activist group Greenpeace has been pressuring Apple to adopt more environmentally-friendly production methods and materials over the last couple of years, and last month responded favorably to Apple's efforts to go green.
Additionally, Apple has posted a page to their website describing not only their efforts toward environmental responsibility with the MacBook, but their overall efforts as a company. At the risk of sounding like a tree-hugging hippie, let me say, well done Apple!