According to this French doctor Kim Jong-il did suffer a stroke:

North Korean leader Kim Jong-il suffered a cerebral hemorrhage but did not undergo surgery and is recovering, according to a French neurosurgeon who treated the reclusive leader in October. Francois-Xavier Roux made the disclosure in an interview with the French daily Le Figaro.

Meanwhile, French intelligence services reportedly checked with a heart surgeon from Lyons who visited the North to treat Kim back in 2004 whether he brought back a blood sample with him and whether Kim had contracted AIDS.  (….)

Roux said declined to give anymore details of Kim Jong-il’s condition citing patient confidentiality. But he added a picture showing Kim visiting the Pyongyang zoo released on Dec. 2 “shows his current appearance. I don’t think the picture has been tampered with.”French doctors say Kim Jong-nam, the leader’s eldest son, is suffering from a congenital heart complaint. [Chosun Ilbo]

I found it interesting that Kim Jong-il may have been checked for contracting AIDS as well.  We can only hope.  It looks like the fattest man in North Korea, Kim Jong-nam isn’t doing to well either with his heart condition.  Maybe that is why he was spotted in France back in October?