Maybe the upcoming BMPCC can be used for s3D too, since the units are equiped with lanc interfaces - similar to the BMCC 2.5K and BMCC 4K.
Given the dimensions of the units I think it is more likely to use them for a beamsplitter rig - but maybe also for a side-by-side rig. We do not know at the moment how well the lance interface would work with existing controllers. Nor do we know really what kind of objectives should be used - the crop factor is about 3 for the BMCC, better for the BMCC 2.5K and 4K. But given the fact that the company does not offer lenses by its own, it will be a search a little bit what kind ob lense will work fine for the BMCC.
The beauty could be that these units offer the acquisition in 10-bit footage, using codecs like ProRes 422 - what would be fine for broadcast stations too. And the units will have the dynamic range of 13 - what is fine. However, there will the be "drawback" that somebody has to make a grading with the DaVinci Resolve Lite grading software, what is part of the BMCC - but for s3D you will need the DaVinci Resolve Software for additional $995 what is part of the BMCC 2.5K and BMCC 4K, but not ot he BMPCC. And the drawback seems to be that this requires additional learning and is described as very time consuming.
The question with the lenses will also be a question for the 4K unit - since 4K will require some more expensive and high-quality lenses too. And t he BMPCC could end up with a lower resolution compared to a GH3, maybe given the sensor but also the grading requirements in DaVinci Resolve.
I think it has become a little bit a hype too - the Blackmagic cameras. But it seems to be be an interesting hype!