Hey Jim
Regarding the GH1 "hack", while it improves the motion video quality, doing so will void the warranty. I got it from very good sources that Panasonic received several "hacked" cameras where the Venus engine was toasted. That's an expensive repair - I've heard $500-$700
Later GH1's were modified to prevent the hack. The GH2 did raise the sampling rate, but not via firmware. The Venus engine is totally revamped and they added a third processor. I think that alone tells us that if it was only a matter of changing the firmware, that's the route they would have taken.
I don't think Panasonic wants to cripple any camera. It's more about a conservative and reliable design rather than driving at full speed all the time.
Later GH1 hardware was NOT modified to prevent the hack. The hack written by the hacker was contained in a software tool. (He was very careful not to circulate hacked firmware, most of which is copyrighted.) The software tool takes existing Panasonic firmware(any firmware up to and including Ver 1.33), and allows the user to change parameters in the firmware. The user can them load the modified firmware.
The Panasonic firmware that was factory loaded after June 2010, was Ver 1.34, which has NOT been released on the Panasonic website. This firmware does not allow any firmware without the Ver 1.34 firmware format to be loaded. (for example Panasonic Ver 1.34 or 1.35 which is not available). If Ver 1.34 was released in the Panasonic website, the hacker could update the tool for 1.34, allowing modifications to 1.34, and be loaded as Ver 1.35
Although loading the hacked firmware would void the warranty, ticking boxes in the software tool can set the firmware version to Ver 0.01, so the original firmware can be reloaded.
The GH1 highest bit rate on video is 13Mb/s. In my view, Panasonic HAVE crippled the GH1 video to some extent, as the hack can provide higher bit rates, and more frame rates (for example 24p & 25p at 1080p), along with some other features like unrestricted video time and more languages. The problem regarding toasted Venus engines, as I understand it, is where users have tried very high bit rates (e.g. 80Mb/s), instead of sensible bit rates up to around 30-40Mb/s.
The GH2 takes the next logical step, providing a higher bit rate of 24Mb/s with better hardware, but at a later stage, it's likely a hack would improve the video further.