User don_parrot has done some testing of the AF with the new firmware.
Tracking-Test E-M5 mit Firmware 1.2 - a set on Flickr

And found the Olympus lenses work better than Panasonic. Surprised? Nope.
A Day at the Races - Micro Four Thirds User Forum

What did surprise me is that the EVF speed and image contrast setting affect the AF.
I would have thought that the AF image pipeline would be optimised for AF - instead it seems to use whatever the user has set on the camera.
That implies there is only one image processing path, not two.