2. Tim Cook, Apple
One of the biggest indicators that 2011 was a historic time for executive moves is that the HP Apotheker/Whitman circus didn't even register as the most notable IT executive transition of the year. No, the biggest of them all happened down the road a piece from HP at Apple, where Steve Jobs, iconic founder and longtime CEO, resigned in August, his health failing. Taking the late Jobs' place was longtime deputy Tim Cook, who had been COO, and also joined Apple's board of directors. Cook is now charged with continuing Apple's astounding growth and keeping investors grinning from ear to ear -- no easy task considering the man he replaced and the legacy that man left.