Because the BMCC EF model will hopefully be available months before the BMCC m43 model, the EF model is more “valuable” to me than the m43 model.
I’ll also occasionally make use of some of the auto features of the electronic EF lens mount that the BMCC m43′s “passive” (purely mechanical, not electronic) lens mount doesn’t offer.
If the BMCC m43 were an electronic mount, I might have waited for it because I own a few electronic Lumix lenses. But the BMCC m43 mount is passive, not electronic. And I don’t own any manual native m43 lenses, and won’t soon be buying any.
I'm also not aware of a manual m43 lens equivalent to the electronic Tokina 11-16mm f2.8 zoom, or the Sigma 8-16mm f4.5-5.6 zoom. I'll probably get one of these <$700 lenses for the BMCC EF.
So for me, “A BMCC EF in the hand is worth two BMCC m43 in the bush”.
Next year I’ll consider buying a BMCC m43 as a 2nd cam for alternate angles, and as a backup camera, e.g.: relatively inexpensive “insurance” for when things inevitably go wrong.
Other people may have different reasons and situations, and thus make different decisions. That’s OK. It’s all good.
There’s not 1 perfect camera for every production.
The crop factor is to great for my use on the EF version, but if you are OK with that then it will work OK for you. I am opting to go with with the Minolta/Sony lenses and use an M43 adapter that has an aperture control ring. All the Sony/Minolta lenses have a manual aperture control via little arm on the back of the lens. I think I am the only person that is catching onto a Sony A99 with all the Alpha mount lenses and followed up by a M43 BMD camera when it comes out. I think this combo is great and will allow you more lens options and a wider angle of view than any other solution.