With the extraordinary developments in the technology sector, this has happened in a way that seemed inevitable. In yesterday afternoon's crisp, matter-of-fact letter, Steve Jobs told Apple's board of directors and the world that he was unable to continue as the company's CEO. He asked to serve as president and recommended that Apple COO Tim Cook succeed him as CEO. And he said Apple's best days were long gone and expressed gratitude to his colleagues. Of course, hopefully Jobs chose this particular week to step down as CEO not because his health left him no choice, but because he felt Apple was ready. move forward without his daily involvement. If so, his timing was impeccable. The iPhone and iPad are huge successes that have left most of Apple's competitors baffled; Apple's market capitalization, revenues and profits have all surpassed those of Microsoft. Simply put, it is the most important technology company of this era. In a way, this week's news simply ratifies an existing reality. Since January 2009, Jobs' two medical leaves have reduced his role by a total of approximately thirteen months. With Cook as interim COO and longtime Jobs collaborators like design god Jonathan Ive and marketing chief Phil Schiller, the company continued to create successful products, generate buzz, and generally thrive. (See photos from Steve Jobs' legendary and visionary career. )Thanks to the iPhone and iPad, Apple is remarkably well positioned to thrive in the post-PC era, especially if Jobs continues to step in as president. But what happens when a CEO famous for micromanaging every aspect of his company's products officially retires from managing them altogether? It helps that Jobs' vision has been so consistent for so long. In 1976, with... half the paper... several generations of these devices to come. (Find out why Steve Jobs' resignation shouldn't be a surprise.) Apple can't simply churn out better versions of today's products, though. He needs to figure out what the next big step is and do it better than anyone else. It must ensure that the historic achievements of Jobs' two tenures at Apple – Apple II, Mac, iMac, iTunes, Apple Store, iPod, iPhone and iPad – are followed by historic products in new categories. If the company manages to do this in the years ahead, it won't be proof that Steve Jobs has proven replaceable. Instead, it will be proof that he taught the company, which so many fans and detractors believed was a one-man show, to continue to be Apple without his intense involvement. It would be Jobs' last and best thing — and right now, the odds look good that he'll pull it off..