Does the i7-3930K give enough performance increase over the i7-4770K to justify it's exuberant price tag?
Is the i7-3770K now obsolete?
Go with 4770K or you can wait for Ivy-E which will be out prolly around october-november this year and will have a noticeable performance increase over 2 year old Sandy-E (3930K) for almost the same price.
4770K and 3930K's difference in performance http://www.anandtech.com/bench/Product/836?vs=552
<-- This will give you an idea. And IMO, 3930K is not worth it right now as Ivy-E is on its way.