The election is to be formally announced on August 27, and the voting will be on August 29, according to Jiji Tsushin (8/26/2011).
Jiji reports that there will be 5 candidates for the job. But it seems to boil down to two leading candidates backed by two warring factions within the DPJ.
On one side is Seiji Maeda, 49 years old former Minister of Foreign Affairs, backed by PM Kan and his faction. On the other, Banri Kaieda, 62 years old Minister of Economy, Trade and Industry, backed by the faction led by Ichiro Ozawa and ex-PM Yukio Hatoyama, both of whom like to be the "king maker".
Banri Kaieda has been an unabashed proponent of nuclear power as the Minister of Economy, Trade and Industry that oversees the nuclear industry in Japan.
5 candidates are:
Seiji Maehara, age 49, ex-Minister of Foreign Affairs
Yoshihiko Noda, age 54, Minister of Finance
Michihiko Kano, age 69, Minister of Agriculture, Forestry and Fisheries
Sumio Mabuchi, age 51, ex-Minister of Land, Infrastructure, Transport and Tourism
Banri Kaieda, age 62, Minister of Economy, Trade and Industry
Take your pick.