A dark cloud is hovering over Apple's collective head: Analysts expect today's earnings report, to be released after the closing bell, to show the company's first drop in profits since 2003. Their estimates, as reported by Bloomberg and the Los Angeles Times, peg the fiscal Q1 net income sinking about 2% to between $13.41 and $13.48 a share. And consider this: With the exception of a single quarter since 2003, Apple's profit has jumped more than 10%. What you need to know before the report, which Tim Cook and Apple's CFO will follow with a conference call that one Barclays analyst has dubbed "the most important ... in years":