Thanks,
at a glance, the Olympus Zuiko Digital comes out slightly ahead of the Pansonic Leica D, with the main differences in the corners: more sharpness and less vignetting. That is fairly consisent with the most commonly claimed strengths of the Olympus 14-54, and of Zuiko Digital lenses in general.
On distortion, I think it says that the Olympus maybe has slightly less barrel distortion at the wide end, but not much difference. (This is consistent with my experience of the Olympus 14-54: easily the least vignetting at the wide end that I have seen in any lens of comparable zoom range.)
More evidence against the myth that the mere involvement of a great German lens maker will produce better lenses than any Japanese lens maker, regardless of price constraints.
Still, the gap is maybe not great, and if one has a use for OIS, the Leica 14-50 is tempting. Panasonic has announced that it will be sold separately from the body, so I wonder what the price will be?