On the Longevity and Sustainability of Mac's Green Laptops

From the Technically Green blog:

Is it okay to go through a new laptop every year or two if they are easier to recycle and less likely to leach harmful toxins into our ground water?…I see some dubious green-washing in Apple’s new line of MacBooks. No matter how recyclable a computer may be, more upgrades in shorter cycles means more resources and more energy consumed. And that is a step backwards in sustainability.