This is a dilemma for me. I don't shoot professionally but have a 5d3 to make videos, which I enjoy very much. I'm very tempted with the a7s because of the image quality. The only reason I'm hesitant is that, Sony will probably release one in a year or so, with internal 4k and improved rolling shutter and I'm unfamiliar with the resale value of such a camera. With canon, you know that the resale value of a camera won't take a huge hit because of the enormous customer base they have. I'm not sure who you could sell the a7s to if a newer version with internal 4k comes out. I don't think photographers will be looking to buy a 12mp camera, and videographers will surely want to move on to the newer version. So what are your opinions on the resale value, do you think it could fall by 1k this time next year?