One day after posting the Olympus M.Zuiko 9-18mm review Photozone also published the Panasonic 7-14mm test! The Panasonic lens performs a little better but you also have to keep in mind that it cost 30-40% more than the Olympus lens!
Check out the price of the Panasonic lens on Amazon
and the price of the Olympus lens on Amazon
Read the review: http://www.photozone.de/olympus–four-thirds-lens-tests/530-pana_714_4