Apple's CEO, Tim Cook, will be speaking at the Goldman Sachs Technology and Internet Conference tomorrow, and it's been moved up to an all new, all earlier time-slot. According to Apple investor relations:
Apple CEO Tim Cook will speak on February 12, 2013 at approximately 7:15 a.m. PT/10:15 a.m. ET. A link to the audio webcast will be provided.
Cook spoke at Goldman Sachs last year as well, one of his first public speaking engagements after taking over as CEO at Apple.
Source: Apple investor relations