According to the official website of anime "Sora no Otoshimono
", the previously announced
3rd season of the TV series has now been replaced with a second movie
due for release in 2014. It will have new story and will be made with the same staff as the TV series. The news of the movie is also reported by the jacket wraparound for the newly released vol.18 of the manga.
Source: Official anime website
, wrap of manga vol.18
Previous related thread: Third Season of Sora no Otoshimono Confirmed