EditShare, the company that currently owns Lightworks, has updated their web-page with a November 2010 update. Beginning 29 November, the open-source Lightworks will be available for free to those who registered to access this application. There's full capabilities for capture/playback, editing, effects, tools, and other film features. New to the open-source edition of this program is a basic wizard, a new user-interface, on-screen console controls, native support for new formats, a new project browser, and much more.
While these improvements are great, the platform support is currently limited to Microsoft Windows. Support is now available for Microsoft Windows 7 32-bit and 64-bit, along with Windows XP 32-bit, but that's it. They are looking to port Lightworks to Linux and OS X still, but they say that won't happen until late 2011.
For now if you're into Linux video editing you'll have to use the recently-released Cinelerra, OpenShot, PiTiVi, and the various other free software projects that have attempted to make a viable non-linear video editor to varying levels of success.