According to the handbill of GAGAGA Bunko, Gatoh Shoji
will start a new novel on the publisher. Gatoh was planning to publish the final volume of "Full Metal Panic!
" novel when Sakura bloom but they have already gone in Japan.
Scan of the handbill
Gatoh's official blog
Updated on Oct 23rd
According to Dengeki Hobby Magazine December issue, Gatoh finished about half of the next volume of Full Metal Panic novel.
Source: Scan of Dengeki Hobby Magazine
Updated on Nov 12th
According to GaGaGa Bunko, the title of the new novel is "COP CRAFT: DRAGNET MIRAGE RELOADED" and it will be released on November 18th. The illustrator is Murata Range
Updated on Jan 6th
According to the official blog, Gatoh said he wants to release the final volume in the "Spring". A new short episode will be released in Dragon Magazine March issue (Jan 20th). The short takes place in Jindai High when Sosuke and Kaname were in the second grade.
Source: Gatoh's blog