Hello, I'm hoping this would fit into this topic.
I've currently got a i7 2600k CPU and it's the oldest thing in my computer aside from the motherboard.
Aside from music/other media I really only use my PC for gaming, Dwarf Fortress being my main interest.
I'm hoping someone can shed light on a new CPU (or one coming out soon) that would benefit me
Any CPU worth upgrading to will require a new motherboard, so you'd want a Skylake chip. This, plus motherboard and RAM, would cost you in the $5-600 range. If all you're running is DF I doubt it's worthwhile - DF remains a single-thread game for the most part, and the Skylake equivalent of what you have is not that much faster in single-thread performance. For other games, particularly modern AAA titles, the multi-thread performance would be a major boost (I have a non-K Skylake i5 that trounces my friend's i7 of similar vintage to yours), but that's an entirely different question.
I do play other video games, GTA5, The Witcher & Cityskylines would the most recent. Would a Broadwell do nothing for DF ?
For those, you'll get a very noticeable improvement in performance with a new chip, but there is no reason to buy a Broadwell.
Broadwell is an outdated architecture, and will generally be
more expensive for
lower performance. There are a few Broadwell-E chips that are more powerful than the best Skylake chips on the market right now - they have more cores, slightly worse single-thread performance, cost a thousand dollars, and still need a new motherboard. If you're playing modern AAA games, get a nice Skylake - a top-end i5 with a good motherboard and 12 gigs of RAM will set you back less than $500, and getting a high-end i7 (DF is one of the few games where this would actually be worthwhile, as it relies heavily on single-thread performance) wouldn't bump you up past 600. You'd probably be able to keep your existing PSU, as the much newer architecture than you have provides drastically reduced power usage.