Stop looking for reasons to upgrade your machine. You said it yourself - the new chips are HASWELL REFRESH. It's the exact same chip but with freaking 100 more mhz.
I expect that you have already overclocked your CPU, because if you didn't then why the hell did you even buy the K edition chip. Why am I mentioning overclocking? Well it's simple, do you actually think that these "new" chips will make any difference at all? No, I can garantee you now that you won't see any difference between the two chips except their initial default stock speeds.
This is just Intel getting a new grasp on the market, their chance to change prices around a little. If someone is getting a new CPU from scratch, then yes the new chips will probably be a better buy, presuming that they are priced the same (?). But for upgrade from 4670K?
_NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO_