For those who would like to have a video trailer in their language, I have created a project on Transifex:
https://www.transifex.com/widelands/widelands-promotional-material/
Send me a message when you're ready. I will then edit the captions and create the video.
I will edit the descriptions texts in the videos only - if you wish to record localized game content as well, your will have to do that yourself - I will find a way to get the project video source files and savegames to you then.