"I have always said if there ever came a day when I could no longer meet my duties and expectations as Apple's CEO, I would be the first to let you know. Unfortunately, that day has come."
Which means that a much sadder day is coming, sooner than any of us would like. Steve Jobs is the Edison of the modern age. Edison turned electricity into a part of every household, and defined it. Steve turned computing and the Internet into ubiquitous personal accessories, and defined them (within that mode as ubiquitous accessories).
Neither Apple, nor our world, will be the same without him in it.
UPDATE: Steve's best quotes.
Jobs was on the losing end of competition many times, but he kept coming back. He didn't sit around and whine about how he'd been robbed and pushed out. He may not be the biggest name of the IT Revolution, but he's the one I like best.
Jobs' formula was simple enough. Passionately care about your users, guide them towards the good stuff, be willing to subtract the lousy, and always keep your eyes open for the next big thing.