For millions of Apple fans, Steve Jobs is irreplaceable. But since being on Medical leave for an extended period of time has elected to stand down from his position. Tim Cook, Apple COO will be leading the team going forward.

In a brief statement to the Apple board and “the Apple Community,” Jobs gave no reason for his decision other than:

“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.”

Apple subsequently confirmed Jobs’ appointment as chairman and Cook’s appointment to the CEO role and appointed Cook to the board. However it gave no indication of a future executive role for Jobs.

Jobs was ejected from Apple in 1985 and brought back in 1997 when the company was on the verge of bankruptcy. He has been credited with being the creative force behind a host of its subsequent highly successful innovations, starting with the 1998 iMac – the first personal computer that was not a boring beige box. This was followed by the iPod, the iTunes music store and the iPhone, the device that shook up not only the personal computer industry but also the global mobile phone industry dominated at the time by Nokia.

Every since Apple revealed that Jobs was suffering from pancreatic cancer there has been much speculation on how Apple would fare without him. However at present although Jobs is clearly stepping back, there is no suggestion he is walking out. Much will likely depend on the state of his health, about which nothing new has been said.