So, my personal opinion. I'm assuming that Corsair will stay in mostly gamer mode, so I'm not going to say anything wild like suggest that you make a 60% board.
A few observations from a more moderate standpoint.
I don't mind having non-mechanical keys on the f-rows/six nav keys if it'll shave $10 off the cost. Honestly the only protest would be on principle, which I find less important than savings and efficiency.
Also, the open aluminum casing is great. Very strong, easy to clean, and looks wonderful. No need to change that, but having both brushed and anodized black available for all switches seems to make sense.
The aesthetic is good; the branding is there and not obtrusive, and looks quality as it's actually metal rather than printed, but as I think some others have said having standard keycap sizes would be good. Lots of modders, and I've never seen a single modified Corsair board for that reason. In fact, if you offered different colored keycaps as an option, like white, I feel as if it would be very popular with us as well as the general public. I would definitely want to get a white-keycap Corsair board, because I already like the board itself and the font is readable but different enough that it's better looking than a 1990s keyboard.
As far as the build, I understand that there are two cables, which necessitates the cable being very thick, but making them even slightly thinner would be good. The cables on my K60, while never being able to be accused of tangling, are rather large (love the braiding, though). Another option or thing to put in conjunction is having channels, and given how there's already a raise at the top of the board, it would seem like it'd be good to take advantage of that feature.
Also, a TKL version of the K70 is pretty much a must. Most all of us have different tastes in switches than just Red, so having the most popular keyboard of yours in the more common layout would seem sensible. Even having the K65 with an option of different switches is fine.
Other than that, the little touches of quality in you guys' work is is just great. The metal name, aluminum design, volume drum (which none of my other boards have) and cable are just some of the touches that I've come to appreciate from all of you.