I tried them, build my own, designed and redesigned them myself and ended up finding such rigs way too large.
They remove the biggest advantage of a micro4/3...size+weight.
If you use a rig, it should be foldable, lightweight and pulled out of the camera bag and set up within seconds.
Having some more sturdy mounting options then just 1/4" at the bottom, hotshoe at the top and maybe the filter-threads of the lens would allow for more lightweight rigs. Integrate a cage into the body.
(BTW, taking appart and reassembling a GH2 is no magical process. It's just a computer like any other one.)
Examples of where the GH2 has it's unique selling points:
Bringing 3 bodies and 6 lenses to a short-notice or improvised interview shot in a small backpack with enough space for sound, power and light.
Having a body constantly in your pocket with a pancake lens where otherwise you would miss some perfect B-roll or compositing material because your heavy DSLR-body or upper class camcorder is in the hotel room/car/bottom of the backpack/whatever.
Switching bodies instead of lenses and thus be faster and more versatile then a full frame shooter.
Just mounting a body with a wide angle on top of a body with a tele and cut between them in editing because both are so light and small that it's no big deal.
you nailed it in one.
My little housing for the nex 5n is specifically designed to remain handheld in the same way a DSLR can be carried around all day ready to get that money shot no one is prepared for. With the screen folded down, it takes up less space than a popular walk around combo of 5D and 28-70 f2.8L lens so can be packed into a backpack in its entirety during heavy rain. Being a case structure instead of a frame, the ABS structural integrity is similar to aluminium. There is no flex. It is a rigid as if I were to have the case machined in aluminium. However the case, fan system, clm-v55 screen and hand strap adds only a small amount of weight to the overall rig. Id say with a little 50mm prime on the front it weighs in only slightly more than a canon 5d with the same lens. With the Anamorphic lens on there, 4x4 Mattebox, ND's etc it is a little hefty but still manageable for a days work.
That tech noir rig looks lovely, it looks pretty big for taking anywhere other than a film shoot though. You would need a rather large flight case to hold that lot set up and ready to shoot with. I am amazed at the price for it though. Someone has done well to get it priced so reasonably. Seems an awful lot of machined aluminium for the small amount of money! I really like the machining work. I cant find any info about Tech Noir online. Anyone got a web address for them?