Intel decided to refresh the dying and aged 1366 platform, so they refreshed their banking accounts with your well earned money and give you in return meh gains. The only thing good about the X79's are the Motherboard features, which incidently AMD have been offering for well cheaper for sometime.
A 2600K is very comparible with the SB-e chips, maybe 10% slower worst case scenario, SB-e like Bulldozer = avoid at all cost unless you are a sugar daddy or have a sugar daddy, in which case you can buy me one as well.
The X79 is the chipset for our socket 2011 based enthusiast processors like the Intel® Core™ i7-3930K and the Intel Core i7-3960X Extreme Edition. It is design for applications that take can advantage of high memory bandwith and are heavily multi-threaded. So if you are doing something like Adobe CS than there is an advantage to using these processors.
Very few games can take advantage of more than 4 threads right now. For this reason the extra cores and hyper-threading on the Intel Core i7s have minimal use in a gaming system. So if you are looking to build a gaming system; the Intel Core i5-2500K is the processor of choice right now.