Steve Jobs resigns as CEO

http://www.engadget.com/2011/08/24/steve-jobs-resigns-as-ceo-of-apple/
http://www.apple.com/pr/library/2011/08/24Letter-from-Steve-Jobs.html
http://www.apple.com/pr/library/2011/08/24Steve-Jobs-Resigns-as-CEO-of-Apple.html
http://www.engadget.com/2011/08/24/steve-jobss-apple-a-timeline/

I think it's because of his health. Being a CEO is exhausting even for someone in good health, and he hasn't been very well recently. Hope he feels better soon!