FDR-AX1 is the Sony Handycam that will allow producers of video to really play with 4k. With a very familiar body, the FDR-AX1 should fit right in with cameras that you've used before. When we see the camera, we're left with a "wow" because cutting edge technology is made tangible, and by getting the price below $5,000 with video output via HDMI, 4k video gets as close as ever.
Panasonic looks to leverage what they've done well in the past. The HC-X920 takes the HC-X900 up a notch with an image leveling sensor, built-in Wi-Fi, and 20.4 megapixel still photos. It reprises the manual ring around the lens which we are big fans of, and while manual control is nearly always our mantra, Panasonic looks to make image stabilization automatic and enhanced with with Level Gauge which does vertical and horizontal axis corrections to fix minor tilts to make such human error difficult to see.