The International Crisis Group has a decent briefing on what they expect LMB will do for the Korean peninsula. Pretty much the same old stuff, including:
Lee is expected to continue South Korea’s efforts at rapprochement with North Korea but to press more firmly for reciprocity than his predecessor. He has outlined a plan to narrow the economic gap by providing the North investment and help in creating an export manufacturing economy. There is widespread consensus in South Korea on engagement with the North, so the only change anticipated under Lee is a greater emphasis on holding Pyongyang to its commitments.
But the value of the piece is in its level of research. Unlike most pieces which rehash research from other sources, ICG has a strong reputation for actually conducting the research itself! Make sure you give it a read!