For what it's worth, I have the 3930K with Sabertooth x79, and a 4GB GTX 680. It's been 4 months, no problems so far. Haven't done a ton of video editing, but this card, or even a 570 would be great for Premiere.
The GTX 780 has been released, but only a 3GB version. The Titan is a beast, but I heard next year there's a new GPU coming out, so, no need for me to upgrade in the meantime.