There are yet no motherboards with front USB 3.0 headers on board.. All motherboards provide USB 3.0 connectivity option at their back panel (2 ports being the norm).. So getting a USB 2.0/3.0 front panel chasis does not matters currently.. If you need access to front USB connectors often then going for USB 2.0 front panel cases makes more sense..
This is what I expected to hear. Thanks a lot,
PD: How can I select your answer in order to "solve" the post?