Of course it won't.
Anyone would be stupid to rule it out, and some goes for video.
The questions is if/then, not if it's a bad idea or not
The thing I wonder though is:
* To make a camera with decent video and in this case without a mirror you need fast contrast-detect focus? Right?
* And when you got fast enough contract-detect focus why should you keep the mirror and the pentaprism?
* And if you throw them out will you really want to keep the current line of lenses and big frames? I assume not?
So.. If I buy into a system now will all the current gear be kinda outdated because the mirror and pentaprism and optical viewfinder system is dying?
Because there is a need for the specific distance between the lens and the sensor with or without mirror isn't it?
I like the specs of the Panasonic cameras but micro four-thirds atm gives longer DOF (and it will always be that way), glass is slow (compared to regular four-thirds), glass is quite mediocre (even the 20/1.7 isn't all that great uncorrected) and finally all of it is also expensive .. Will these be issues for all other systems going mirror less? I assume no-one want to keep current lenses/distances if going mirrorless?
So I guess I shouldn't be buying into it. I need/want to choose system but I'm not convinced where to go really.