The open source video editor for Linux LiVES has been updated. It is a free, yet stable and powerful software package for editing digital videos.
It can also be used as a VJ tool for creating images and mixing visuals and music. It includes an RFX builder for creating effects and transitions, and can be extended through RFX plugins. LiVES handles most video formats and common audio formats. A long list of features and editing capabilities can be found here.
Another great open source video editor for GNU/Linux is Kino, which offers easy and reliable digital video editing and works well with IEEE-1394 to capture digital video and provide video tape recorder control.
You can use Kino for example to load several video clips, cut and paste pieces of video or audio, and save it as an edit decision list in SMIL XML format. Besides various DV formats, Kino can export to a variety of other formats, such as MP3, Ogg, Vorbis, MPEG-1,2,4, and WAV. It can also export still frames in most common image formats. For more information see here.