A good non-linear editing software for Ubuntu Linux: LiVES.
I think LiVES is a great alternative to Sony Vegas, in case you switched to Ubuntu Linux as Vegas software don’t have a Linux counterpart. LiVES has a real-time video performance tool and non-linear editing rolled into one, letting you create video right away. I downloaded the program but I don’t know how to operate it yet :p
Visit the LiVES homepage.