According to Meteor, a short manga titled Reibaishi Izuna ~the spiritual medium~ by Okano Takeshi and Makura Shou will start in the August issue of Oh SUPER JUMP. The manga will feature Haduki Izuna from the Jigoku Sensei Nube (Hell Teacher Nube) series.
According to Canned Dogs:
Senaka: Otaku Road reports that with the Japanese release of Tenjho Tenge Volume 17, Oh! Great's seinen manga, which began serialization in 1998 in Ultra Jump, will have sold over 10.7 million copies.
Japanese idol Shoko Nakagawa (actress, seiyu, illustrator, singer and more), also known as Shokotan, will finally be able to achieve her "childhood dream" of becoming a mangaka with the debut of her six-part series Noushi no Koi in the upcoming issue of Ohta Shuppan's quarterly magazine Hon-nin (on sale 9/8).
A commercial for Honey and Clover creator Chica Umino's upcoming series, The Lion of March, can be found on Young Animal's website. The new manga will begin serialization in Young Animal issue 14, on sale 7/13.
Also available is a commercial for Kiminori Wagasugi's Detroit Metal City.
Source: Ultimatum Tidbits
From Kadokawa Shoten comes a new magazine called Zoukan Ace A Assault. The 2007 Summer issue will be released on July 10th, and will carry extra chapters (side stories) of popular serializations such as Mirai Nikki, Garei, Fate/stay night and The Melancholy of Haruhi Suzumiya.
According to a Super Dash Bunko advertisement that appeared in Weekly Shounen Jump No. 32 (7/9), Katayama Kentarou (Author) and Yamamoto Yamato (Illustrator)'s light novel series Kure-nai will be adapted into a manga.
The new manga will start in the first issue Shueisha's new magazine Jump Square (11/2). A preview of the manga will appear in Akamaru Jump (on sale in August).
In celebration of Tantei Gakuen Q (Detective School Q)'s TV series premiering on July 3rd, the popular detective manga from Seimaru Amagi and Fumiya Sato (the duo behind Kindaichi Case Files) has resumed serialization in issue 30 of Kodansha's Weekly Shonen Magazine.
The manga, which began serialization in Shonen Magazine in 2001, originally ended in 2005.