According to Famitsu, SEGA is planning a sequel to Valkyria Chronicles. Titled Senjou no Valkyrie 2: Gallia Ouritsu Shikangakkou (Valkyria Chronicles 2: The Gallian Royal Military Academy), the game will be released for PSP during the next Winter.

The game will take place 2 years after the original, during a Civil War that breaks out in the southeast of Gallia. The military is unable to stop the rebellion, so it's up to the students to take care of the situation (hence the subtitle, we guess)

We'll post more info as we get it. In the meantime, check the Famitsu scans below

Source: 2chan Famitsu Scan.

Credits to StarScream for posting the scan, and to wenlan for helping with the translation