Biofos (Click here) has some news from Olympus UK about the Four Thirds lens support: “No AF improvement on 4/3 lenses I am afraid“. But Olympus made it also clear that they are working on that issue. Their goal is to make Four Thirds lenses fully operable on m43 cameras.
http://www.43rumors.com/new-olympus-e-m5-news-roundup-new-e-m5-accessories-and-info-abotu-four-thirds-lens-support/