Upload & Sell: Off
As long as it's as easy to remove as the a55 mirror, I'm okay with it. I still love the OVF of the a900, but the EVF on the NEX-7 has grown on me, so I wouldn't be completely adverse to switching, particularly if it's an improved EVF.
I could deal with the EVF, particularly since it would likely be even better than the already good one in the NEX-7. I don't know about removing the translucent mirror. Seems like it might possibly result in some sort of issue since the camera would have been designed with it's use in mind. For instance, is it's effect taken into account as part of the AA filter? Would the camera be more prone to moire without it? Color balance/ WB (is it truly neutral)? Other decreased functionality/ changes (exposure metering, ISO)? I have no idea, just wondering what other aspects the translucent mirror might effect in the camera design.