If your main use for the system will be heavily multi-threaded then yeah its probably worth getting the 3770k, and so long as you're not intending on playing games like BF3 or Crysis at anything other than the lowest settings then it should be fine.

Depending on what you're using to edit though it might be worth nothing that many editing programs are now capable of using gpu acceleration, and as such if you got a better card it would significantly speed up editing with such programs, and make your gaming performance a bit better