Regarding the resolution on the CV1, there's a few things that can really help it 'feel' higher res
1) actually higher res (duh)
2) better subpixel arrangement -- the DK2 uses a display from a Galaxy Note 3. This screen has a pen-tile sub-pixel arrangement. What this means is that the red and blue channels in the display don't actually display true 1080p images. So, while it definitely looks better than the DK1, it doesn't look as good as what a full-subpixel 1080p screen would look
3) better pixel pitch -- pixel pitch refers to the ratio of the actual light-producing part of a sub-pixel to the dark space between sub-pixels. A perfect screen would have them essentially touching each other, but as you can imagine that's easier said than done.
4) Optics -- I don't know exactly what they're talking about with better optics improving the 'look' of the resolution, but if I had to guess, I would say that they're no longer using a perfectly spherical lens, and the new lens gives a bit of bias toward the center of the image. That is to say, the middle of the image is 'zoomed in' less, so you have more area of the actual screen in your direct forward field of vision. The side effect to this would be that your peripheral vision would be even lower resolution, to compensate, but that might not be noticeable because the blur from being out of focus on the edges would probably hide that, anyway.
---The ultimate screen! ---
I have a vision in my head of what the ultimate Oculus screen would be, and the delightful thing is that I don't think the technology is that far off!
Right now, the image gets really blurry as you look away from center. This is because you have a flat screen, but a curved lens. As a result, the screen moves out of the "focal point" of the lens toward the edges. As long as we have flat screens, not only will we have this focus limitation, but a practical FOV limitation, too. You can get more FOV by using multiple screens, definitely, but problems arise very quickly that make the same level of cost-efficiency and ergonomics hard to achieve.
THE CURVED DISPLAY WILL SAVE US!
If you're a gadget person, you will probably have noticed all the work Samsung has been doing recently with curved and flexible displays. THIS is really where things are going to be going, with VR, in the relatively near future. I doubt CV1 will have a curved display (would be awesome if it did!) But I would be willing to put down money that CV2 would.
With a curved display, you would have the display 'wrap around' the lens, so that every point on the display was the same distance from the corresponding point on the lens! This means that you could have perfect focus across the entire screen. It would also mean that you could get trickier with the optics, because you can vary both sides of the equation.
Exciting times, methinks!