That is what i was trying to say. It makes sense if you already have all the other stuff, otherwise not so much. I do hope it has enough impact on market in some way, the idea is pretty awesome.
Don't forget the fact that every lens you buy suddenly has a double purpose (with and without speedbooster). And you don't have to buy f/1.4 lenses anymore, you can pay less than half for a f/2 and have the same light gathering capabilities. Even a dirt cheap f/2.8 prime makes a nice f/2.0.
For example: I'm interested in buying a reasonably fast (at least f/2) standard lens (50mm equivalent) and a wide angle (35mm equivalent) for my GH2.
I could buy a Canon FD / Nikkor 24mm f/2 to get the 50mm equivalent, that would cost €300 to €400 on eBay.
To get a 35mm equivalent, I'd need a 17mm. I could buy some crappy, rare, huge 17mm f/3.5, but that's not fast. The only choice is a Voigtlander 17.5mm f/0.95, for €1200!
With the Speed Booster, I could buy a Nikkor 35mm f/2.8 for €100 to get 50mm f/2 and a Nikkor 24mm f/2.8 for €200 to get a 35mm f/2.
For the price of the Voigtlander 17.5mm, you could buy the Samyang 24mm f/1.4 and the Speed Booster, and get pretty much the same effect: 35mm f/1.0. Plus the added bonus of all your lenses suddenly behaving the same as their much more expensive counterparts.
It is not cheap. But if you are in the market for a a few fast standard/wide lenses like me, then the Speed Booster instantly pays itself back. Plus you get options that aren't even possible without the adapter.
To me this actually is the most exciting product I've seen in years. Yes, we have seen a lot of technical developments on the camera side. Better sensors, cheaper camera's... Nice, but glass always stays the same. Nothing changes physics. Good glass is expensive. In a way it's nice that this doesn't change, lenses retain their value.
But now Metabones manages to come up with something that turns this very fixed part of photography/filmmaking upside down. If I were Sony (CaNikon are too slow anyway..) I'd instantly buy out Metabones and release this technology inside a mirrorless camera (with A-mount, just fit the element in place of the SLT-construction and use Phase Detection pixels) That would be the break trough cheap 'fullframe' camera and stir the market