The JoongAng Daily has some interesting quotes and tidbits on the subject:
Shortly after the announcement, Chung held a press conference at Seoul National University. “Because of where Korea stands today at home and abroad I cannot just sit behind a desk,” Chung said. “None of the challenges we are facing today will be easy to solve, such as the uncertain macroeconomy, the problems facing people’s livelihoods, the enormous burden on private education spending, the job crisis, social conflict, regionalism and inter-Korean relations.
“I know I have many shortcomings, but I will bring together wisdom and the nation’s experiences to create a stepping stone for social unity and assist the president based on my expertise and efforts to help resolve these issues,” Chung said.
Great, more "social unity" language. Don't get me wrong; I have nothing wrong with a "united" society in theory but calls for "unity" in Korea have generally translated into repression of opposition in the past.
The Princeton-educated economist said he had criticized Lee’s policies in the past, but he had learned through a recent meeting that his economic philosophies were similar to the president’s. “We both think competition should be encouraged in principle, but those who have fallen behind must be warmly cared for,” Chung said.
Some "progressive" economist. So it looks like we have a centrist social liberal economist who cares about the poor. Nothing really shocking there.
Does this show a policy shift for President Lee in general? Time will tell; personally I doubt it will change that much. However, it does show a move towards a different more "subtle" political strategy when it comes to the public. President Lee is probably borrowing notes from the late Kim Dae-jung who also had former opposition act as his Prime Minister (Kim Jong-pil).