NEW YORK ( TheStreet) -- Apple ( AAPL - Get Report) shares slid Tuesday as investors braced for more news on Steve Jobs' illness. The Apple chief said Monday that he was taking a medical leave for an unspecified reason and that COO Tim Cook would head the company as the day-to-day manager in the interim. The move comes just as Apple gets set to release December quarter numbers later today, which TheStreet will live-blog. And while analysts expect Apple to post blowout numbers on strong sales of iPads, iPhones and Macs, the stellar financial performance will likely be overshadowed by worries about the extent of Jobs' illness.
Jobs battled pancreatic cancer in 2004 and underwent a liver transplant in 2009. No. 2 executive Cook stepped in to lead the company during those absences, and he is widely seen as the next CEO should Jobs not return this time. Having a succession plan and a fairly clear product roadmap for the immediate future lends a bit of stability to the situation. But for those who see Jobs as the singular visionary behind Apple's success, there will be bigger concerns about the long-term prospects for the company and its stock. Jobs has asked for privacy during his leave, and Apple has never been forthcoming with information during his illnesses, so investors will not have much to go on, it seems. --Written by Scott Moritz in New York.>To contact this writer, click here: Scott Moritz, or email: email@example.com.To follow Scott on Twitter, go to http://twitter.com/MoritzDispatch.>To send a tip, email: firstname.lastname@example.org.