I want to spend a little bit of money now while i have it, and while my wife lets me spend it, so that i have a system that will be good for a few more years. Plus my friends system is 3 years older than mine and my parts that i am giving to him should be a significant upgrade for him, for a minimal price. i want the PCI 3.0 also so that all i really need to buy in the next 3-5 years should be a graphics card, and maybe a better processor in that chipset.
Forget the better CPU in the chipset there won't be anything in that socket after the current Ivybridge next year new architecture new socket.
As you already have a decent GPU yes the i5 would be a good upgrade you chose a K series so you can OC it down the line to prolong its useful life. The other option would be to deck out your current build, SLi the cards, OC the CPU add SSD etc.
The i5 is probably the better route in your case as your after longevity but add a decent cooler (coolermaster 212 evo) if you plan to overclock at all.