Kim Jong Il is dead, long live a relatively unknown factor...

[Zhukov]

Actually, China is doing quite a lot. Short of just taking over the place, they are influencing the economics of the region enough that pockets of government sanctioned "free market zones" exist in the north of DPRK. If things continue as they are, (although that can't be assured) eventually DPRK will be very similar to China as far as economic structuring goes. The ruling elite in DPRK can see that the best way to stay in power/luxury is to give up on a Stalinist vision of socialism in one country, and just turn to capitalism like China when nobody is looking

China is already outsourcing manufacturing to factories in DPRK, and the government there is desperate for the chance to give it's citizens actual work to do that doesn't involve pruning grass or washing concrete. North Korea is on track to be the cheaper, smaller, more brutal version of China.