One big point - Apple supports it's products longer than the rest of the industry, thus they don't end up in landfills as quickly. For example: - The original iPhone was released in June of 2007, and had the newest iOS (3.x) available until the release of iOS 4 in June 2010. - The iPhone 3GS was released in June of 2009, and is still getting OS updates, even to iOS 5 released later this year. How many Android phones…
Apple sells one new device each year and supports it well with updates. Google sells one new device each year and supports it well with updates.
The Nexus devices even have an advantage here, in that Google is not the only party that makes android-based operating systems for the series.