I've shot with the A7 for a full day, you can see the video here:
http://www.youtube.com/watch?v=bnvgceTEV3c
Looking at the image afterwards though, I'm not as excited as I initially was. I loved the process of shooting with the camera, but the image quality is pretty wanting. As you can see on the video above, the image is quite soft, and moire is visible in many shots. Hopefully, this can be chalked up to pre-release firmware, but we permitted to judge the video quality based on the models we had, and I'm not delighted with the results. Once the production cameras come out, I'll post a follow up to the above video with my revised opinions.