If you are thinking of buying an Atomos Ninja for your GH2, it is probably best to wait for the hack.
A few weeks ago I ended up researching how to extract 24p from Sony FS100 footage delivered via a 60i signal to an Atomos Ninja for Philip Bloom and came across some information about the GH2’s HDMI output which I wasn’t aware of previously.
In my opinion, a bug was purposefully inserted into the HDMI output of the camera to prevent the extraction of high quality 24p 4-2-2 on an Atomos Ninja.
The purposeful bug interferes with the timing pattern of the 60i interlaced signal. Due to HDMI TV standards, 24p is transmitted inside an interlaced wrapper. Normally software can perform 3:2 pulldown removal and de-interlacing to extract 24p from this wrapper, but the timing interference makes this impossible.
I believe Panasonic purposefully programmed the firmware to have a random cadence pattern, because HDMI outputs and formats are too well understood for it to be a genuinely accidental flaw.
Personally I think this is very naughty.
The HDMI hardware in the GH2 can do lovely 4-2-2 and 24p, and the firmware messes with it. You can still record footage via the GH2 to an Atomos Ninja or other device but it will not be 24p and it won’t be as good a quality as the internal AVCHD.
Consumer and professional broadcast divisions should operate fully autonomously (and that is the official company line) but clearly this isn’t quite the case.
It is sad to see a firmware team taking time actually to program out existing normal functionality.
Good luck with your hack Vitaliy!