Apple Inc., the world's most valuable technology company,  is set to report earnings for its Q1 of 2011 after the close. While focus on Steve Jobs' health and leave of absence will likely put pressure on Apple  shares, analysts believe the Apple's quarterly performance is still intact.

We continue to believe that Apple is positioned to outperform in this tough macroeconomic environment with its defensible strategic and structural advantages and its vertical integration, Shaw Wu, analyst at Kaufman Brothers said in a note released on Tuesday.

Wu reiterate Buy for Apple and raise 12-month price target to $415 from $395.

For a company's of Apple's tremendous size where consensus is looking for $90.4 billion in revenue in FY11, we believe its nearly 50,000 strong don't receive enough credit for the company's great success, Wu said in the note.

Wu insists unit assumptions for the quarter of  16 million iPhones, 6.1 million iPads, 4.2 million Macs, and 17 million iPods. Meanwhile, he noted that there is room for upside on gross margin as the company's assumption of 36% will likely prove conservative.

Wall Street has forecast Apple's quarterly revenue to rise more than 50 percent to $24.4 billion after a bumper holiday shopping season.

For the third time in roughly 6 years, Apple CEO Steve Jobs on Monday announced that he has taken medical leave to focus on his health. In his absence, Chief Operating Officer Tim Cook will be responsible for day to day operations.  

The news has come at a time when Apple's iPhone has just been arrived at Verizon's network, and iPad 2 and iPhone 5 are rumored to be launched this year.

Cook's third time at the helm might be permanent as Jobs used the word hope when identifying a potential return time, according to Brian Marshall of Gleacher & Company. This, might cause material short-term weakness in Apple stock, Marshall said.

Brian states in our view, Steve Jobs is the 'guiding light' and visionary leader crucial to the continued product innovation at Apple.

However, Wu from Kaufman Brothers said that  Jobs has successfully embedded his way of thinking and philosophy into the culture of Apple.