On multi-threaded applications like some video and audio editing software the 4 extra threads can make a difference between these processors. You can see how they stack up here http://www.anandtech.com/bench/Product/287?vs=288.
As to if it is worth the extra $100 that is all up to you and your budget. If using the Intel® Core™ i7-2600K will save you 4 second for every minute that you are working on it and over the course of the week it might save you around 32 minutes and over a year it may save you 24 hours or more of work or productivity time or 3 days at work. For me that would make a difference in the long run.
Intel Enthusiast Team