Absolute Fanboy

Araragi Koyomi – Kamiya Hiroshi
(Sayonara Zetsubou Sensei’s Itoshiki Nozomu, Natsume Yuujinchou’s Takashi Natsume)
Senjōgahara Hitagi – Saito Chiwa
(Pani Poni Dash’s Rebecca Miyamoto, ARIA’s Aika S. Granzchesta)
Hachikuji Mayoi – Katō Emiri
(Lucky Star’s Hiiragi Kagami, Darker than BLACK’s cosplay girl Kayanuma Kiko)
Kanbaru Suruga – Sawashiro Miyuki
(Sayonara Zetsubou Sensei’s Sekiutsu Maria Taro, Kannagi’s Aoba Tsugumi)
Sengoku Nadeko – Hanazawa Kana
(Kannagi’s Zange, Zegapain’s Kaminagi Ryoko)
Hanekawa Tsubasa – Horie Yui
(The Tower of Druaga’s Fatina, Toradora’s Kushieda Minori)
Oshino Meme – Sakurai Takahiro
(Code Geass’s Kururugi Suzaku, Moon Phase’s Mido Seiji)

From 2ch thread. Except Kamiya Hiroshi and Saito Chiwa, I think the casts pretty match the roles. The first episode, Hitagi Crab: First Part, is scheduled for July 3, 2009 at 23:00 JST.