SLRgear published their Panasonic 14mm f/2.5 test. The lens is very sharp, Chromatic Aberration is somewhat high for this lens, Vignetting and Distortion are negligible. And their conclusion is very short: “With sharp results and only slight issues with CA, Panasonic has produced a very nice walk-around lens “. Read the full review (with image samples and graphs) at SLRgear.
M43photo.blogspot compared the Panasonic 20mm with the new 14mm lens.