Little is known about Kim Jong-un, including his exact age, though he is believed to be in his mid-20s.
However, South Korea's intelligence chief has been quoted as telling a closed-door session of a parliamentary committee this week that a campaign to boost Kim Jong-un's image has been going on behind the scenes due to concerns about his father's poor health.
Al Jazeera's Tony Birtley, reporting from neighbouring South Korea, said that the party meeting could present new challenges to Kim Jong-il and his family, but could be vital if reports that his condition is worsening are true.
"There are reports that Kim may be showing the first signs of alzheimer's disease," he said.
"The problem is that his son is a young man and has no experience whatsoever and the military, which has gained more power in the last few years, may not be totally on board with this transition."
Brian Myers, an analyst at Dongseo University in South Korea, told Al Jazeera that an indication of a planned succession had been a long time coming.
"Kim Jong-il cannot keep putting it off," Myers said.
"We have heard reports, just in the last few days, that he is having difficulty walking and even putting sentences together in a logical way, so it looks like the pressure is on him to engineer a succession and this is the logical way for him to go about it."
The planned conference is an extremely rare event, the two previous sessions being held as far back as the 1950s and 1960s.
Kim Yong-Hyun, a professor at Dongguk University, also in the South, said the conference would be the most important party event since 1980, when a full-fledged convention of all members made public Kim Jong-il's status as successor to Kim Il-sung, his father.
"There will be an important reshuffle of the party's official posts aimed at preparing for an eventual succession," he said.
Kim Jong-il serves as the general secretary of the WPK, besides his official role as the chairman of the increasingly powerful National Defence Commission.
Analysts say the role of the Workers' Party has diminished over the past decades as the North has put increasing focus on its military power, but the party's ideology dictates the political legitimacy of its leadership.
Kim, 68, has also reshuffled the defence commission to put close aides sympathetic to dynastic succession on the panel.
Tensions between Pyongyang and Seoul have been heightened since the sinking of a South Korean warship in late March and it also remains isolated from the international community which condemns its nuclear programme.
South Korea has accused the North of torpedoing the warship Cheonan and is seeking to have the UN security council penalise it.
The North has denied the allegation and warned any punishment would trigger war.
On Friday, Japan said North Korea was a threat to Asia and urged world leaders at an economic forum in Canada, to issue a strong condemnation over the sinking.
A spokesman for Naoto Kan, the Japanese prime minister, told his counterparts from Canada and Germany at the G8 summit that North Korea's alleged torpedo attack is a "threat to the peace and stability of the region".
The two Koreas are still technically at war because their 1950-53 Korean War ended with an armistice, not a peace treaty.