While this information is helpful to those who want to see performance changes immediately, benching on a beta is not a great way of doing it. Work with what you have and re-asses once the final version has been released. That way you can potentially avoid the need for splashing out shed loads of money for no reason.
I think it is pretty obvious an i5 2500k is a bottleneck for powerful graphics configurations pushing over 60fps in some modern games. This will only become more prevalent over time as better looking and worse running games come out. If you have a single 7970/680 then it isn't a problem as you aren't going to be averaging much more than 60fps anyway at 1080p.
I have the same thing in parts of crisis 3. It has been well documented and benchmarked on that game that i7 can really give better minimum/average framerates in some levels (where there is lots of grass animation for example). In some levels of Crysis 3 my gpu usage drops to about ~70% whilst my 4 2500k cores are at 100%.