While it's been long rumoured that Kaz Hirai will become the new president of Sony Corp. in Japan, the company has stated that no formal decision has been made yet.
Despite this, it is believed that Kaz Hirai will become the new president in April, with Howard Stringer retaining his position as the CEO of Sony. Stringer has stated that he won't be stepping down any time soon, with his three-year turnaround planned to end in March of 2013. At that time, Hirai is expected to replace him as CEO too.
It's certainly been a quite rise of Hirai who was previously the president of Sony Computer Entertainment. He was a very public figure during the PSN hack problems earlier in the year, producing a video response to ease the fears of consumers.