The Lightworks open-source announcement was covered in 2010 and was expected for a Linux debut in late 2011, then came November 2011 release plans, but the Linux version was ultimately delayed.
Half-way into 2012, we finally see the existence of the native Linux client for Lightworks and there's video of it running atop Ubuntu.
Embedded below is a video of Lightworks running on Ubuntu Linux. There isn't yet any alpha/beta release of Lightworks for Linux, but it's expected soon. No other new details for this video editor were shared at this time.