I honestly don't know why the new Canon exists, other than as an imager test platform for the inevitable Canon mirrorless system camera. For the same $800, the Lumix at least delivers an upgrade path and vast systemwide flexibility, while weighing an impressive quarter pound less. In competent hands, both will certainly deliver good results.
I think the problem can be traced back to the as-yet undocumented memo from On High to all camera makers, everywhere, commanding: "Henceforth and forthwith, thou shalt include an "X" in thy camera model designations. Amen."
At some point they were bound to start stepping on one another's toes, especially two companies who already had "G" series. (I consider them both guilty of besmirching the legacy of the fabulous Contax G series, but that's a rant for another day.)
Between these two, my money would go to the Panny (the one with one G, one X and one 1). It's more flexible and more customizable and at this point, can take any of a couple dozen system lenses and uncountable "legacy" lenses (including quite a few I already own).
Once upon a time I'd have been all over the Canon, but that time was probably 2006.
Back in the real world, if the E-M5 can really do everything Oly claims, that's probably my entry point into the mirrorless world. I don't kow how many of these new directions my budget can take.
This incompatibility of formats by the big digital camera manufacturers in the mirrorless market has got me scared of buying into any of them. Seems like it would be a good idea to wait awhile for further fallout.
Or many of us could once again end up with a closet full of forgotten junk bearing a label similar to: