Kdenlive is an open source non-linear video editing suite for KDE that uses the MLT video rendering engine. Whilst kdenlive has yet to reach version 1.0 status, major development is still undergoing with a roadmap to reach at least version 0.6 in the very near future. This tool shows a lot of promise for users who want to dabble into video editing, perhaps someone can create a video-podcast on Linux for us. :)
An alternative video editor to Kdelive is Kino. Kino just released its version 1.0 but along with the official release announcement, the developer also announced that no major features will be added in the next 12 months or so but they would rather improve on MLT, the same engine used by Kdenlive. Maybe it is time that the community pitch in and help improve Kino, specially those who love the GNOME desktop platform over KDE.
Why don't you try them out and see which one suits your needs?