Just came across this yesterday and am posting it in for anyone who's interested.

JVC announced new free firmware updates for models in its ProHD streaming camcorder line, including a new 12 Mbps mode targeted at streaming across closed networks.

Version 4.0 firmware for the GY-HM650 and version 2.0 firmware for the GY-HM850 (pictured, top) and GY-HM890 add adaptive-bit-rate streaming, RTMP support for live streaming via content distribution networks, and a new 12 Mbps streaming mode that JVC said provides "production quality images" when used with the BR-DE800 decoder or the private MESH video network that JVC introduced at NAB.

Separately, a version 4.0 upgrade for the GY-HM600 adds a zebra display function, enables simultaneous use of zebra and focus assist, and improves the zoom control presets.

Installed v4 last week. The most useful improvement for me was the addition of RTMP "push"-type streaming. It has been working well to a Wowza Cloud server.

(So did the RTSP "pull"-type streaming previously, but that requires some more network setup - not always possible when using a client's network.)

Simultaneous zebra and peaking on the LCD is another benefit, I think.