I think it's going to be a LONG time, if ever, before we see cases with no HDD/SSD bays. Just look at the 5.25" optical bays... they've been more redundant than HDD/SSD for years now, yet tons of cases still include them. You could argue they have other uses of course (reservoirs, LCD's, fan controllers etc.), but given the fact HDD's/SSD's are hardly going the way of the optical drive anytime soon, it would be a bit odd for a case manufacturer to restrict sales of a product in such a way. I think what we are more likely to see is a shift away from 3.5" in favour of SSD, and more hidden bays in compartments, split cases etc. with a focus on tempered glass, emphasis on visual builds etc. That seems to be the way case design is going, which is fine by me.