One of the five other working groups that China proposed is the WG for normalization of Japan-North-Korea relations. We are allowed to presume this covers the abductees issue. But North Korea is not in any hurry to start even the financial WG, the one agreed-to WG, which supposedly was a sop to the North Koreans for agreeing to the reopening of the talks. Thus, it is unlikely that the five WGs will get any traction, even if they do get started sometime in the not-so-near future.
After all, North Korea has gained bragging rights, China and South Korea will support its economy indefinitely, and the US and Japan have little room to maneuver. This is a recipe for stalemate. Let's hope North Korea contents itself with standing pat. China must understand the potential regional consequences of allowing North Korea to step over the viable weapons threshold. Let's hope it is able to act on that understanding if the need arises.
Perhaps it is for the better that the Japan-DPRK WG doesn't get off the ground for the time being. After all, if there is progress on WMDs, Japan will be forced into assuming the role of natural banker to North Korea. At that point, no progress will have been made on the abductees (there can never be a satisfactory accounting sans regime change), and Mr. Abe would be forced into making the unpleasant choice between accepting the abductees status quo and taking itself out of the WMD-driven process altogether.
Perhaps Mr. Abe is politically better off with a nuclear standoff in place. And, so far, events seem to be obliging him.