I just read a post from Kris Hall, a JVC representative:

"The 600 will have a Version 2.0 as well with additional features.

Including:
Expanded Focus
– 1.5times expansion on both LCD and VF
Knee Point setting :2.5% step increments
(85%-100%)
• White peak :103% added
• Viewfinder indication when outside good
range (up to F8) Warning to use ND filter (Can turn this on or off)
• Rec trigger on Front
– Assignable: REC/White
Balance/Disable (no function)
This is the record button at the front of the camera by the lens
. Additional AVCHD modes"

Coming next month apparently. The one that interests me is "additional AVCHD modes". Could it be 50/60p? Or it could be just plain old 25/30p (which the camera doesn't currently have).

I'd expect 720P60/50.

The new firmware has been released:

JVC GY-HM600U Firmware v0200 (http://pro.jvc.com/pro/attributes/CAMERA/soft/gyhm600u_firmware_v0200.html)

"Adds clip trimmer.
New lower bitrate AVCHD modes.
---Plus enhancements from previous upgrades:---

Improve Focus Ring sensitivity near WIDE end.
Improve One Push Iris performance
Improve dynamic blemish compensation function
Improve Auto Focus performance
Change factory default setting of SHUTTER to OFF
Improve Audio Delay parameters
Improve performance on recharging"

Disappointed to see no 50/60p, or even 25p AVCHD!