Kim Jong Eun does not wield total control over the DPRK military, the Korean Peoples Army.
Kim Jong Eun however is in command of and has control over the Public Security Bureau (PSB), or Secret Police as it were. Meaning of course if he did not have control of the former or elements, he could simply use the latter to eliminate those not cooperating with him.
In fact, I recall him being put in charge of the Secret Police some time ago, and he was particularly tasked with handling the two Al Gore Reporterettes who got snagged in the DPRK and were rescued (and probably later molested in the private jet) by Bill Clinton.
And,
1) Kim Jon Eun has apparantly issued his "ORDER NUMBER ONE" or his first command order. It was to the DPRK military of all people, ordering their appropriate movements and behavior at this time. Interesting that his first order was to the entire country's military. I believe this order came today.
2) Japanese news is also now heavily speculating based on ROK sources that the "heart attack/death on a train" by Kim Jong il is an outright fabrication:
3) Sankei News (conservative) in Japan is openly speculating on the possibility of assassination of Kim Jong il.
I wouldn't have trouble believing that's what happened...and I wouldn't put it past ordered by Kim's sister and brother-in-law. They have such a history I understand, of being ruthless.
I doubt EUN has any power at all..rather a figurehead only. ...and that will remain as long as Kim's sister and brother-in-law can retain the power with the Military and the Money.