Strike Witches Season 2... hopefully it'll expand on the reasons why each of the 501st members fight... the remaining of em that wasn't covered in Season 1... I personally would like to find out Mio's reason for fighting, and why she became the first witch to utilize the units, along with something like a flashback on the invention of the Striker Unit. Also a little bit more information on Dr. Miyafuji.
Another hope is that it could focus on other witches... like one of those episodes that show various sub episode that focus on various aces and their struggle with the war. Sortof simmilar to that one episode of Avatar: The Last Airbender (Tales of Ba-Sing-Se). Maybe for the fans: a sub episode focused on Tomoko.