It looks like Apple CEO Steve Jobs is off to battle another nemesis, and it's not the PC or competing tablets. Jobs announced to his employees this morning that he is taking a medical leave of absence from Apple, leaving Tim Cook to handle the day to day operations at Apple.

You can say what you want about Jobs, but you can't say he isn't tough. His previous medical history includes a bout with Pancreatic Cancer in 2004 and a liver transplant in 2009, both of which he fully recovered from. No specifics were relased about the reason for the latest leave of absence, but more may be released during Apple's Q4 and 2010 earnings release tomorrow.

The full memo from Jobs: (Courtesy of TechCrunch:)

Team,

At my request, the board of directors has granted me a medical leave of absence so I can focus on my health. I will continue as CEO and be involved in major strategic decisions for the company.

I have asked Tim Cook to be responsible for all of Apple's day to day operations. I have great confidence that Tim and the rest of the executive management team will do a terrific job executing the exciting plans we have in place for 2011.

I love Apple so much and hope to be back as soon as I can. In the meantime, my family and I would deeply appreciate respect for our privacy.

Steve