Olympus just updated their roadmap of Micro Four-Thirds lenses with 3 new additions. While already having announced a prototype M.Zuiko 150-400mm F/4.5 TC1.25X IS Pro earlier this year, two other professional lenses are expected but a standard one.
Making its appearance for the first time on a roadmap is the M.Zuiko 12-45mm F/4 PRO which offers a slightly longer reach than the M.Zuiko 12-40mm F/2.8 Pro with a 1-stop smaller aperture which should make it smaller and lighter.
This standard wide-to-normal zoom will be completed by a medium telephoto lens of unspecified focal-length. Given there is already a 40-150mm F/2.8 Pro which is quite substantial, a lighter and smaller lens would make sense. This is a guess as no additional information was supplied by Olympus yet.
In the standard lens lineup, Olympus will add an ultra-telephoto zoom. The new M.Zuiko 100-400mm F/5-6.3 IS will cover a 200-800mm in equivalent 35mm terms. This will make it the longest interchangeable zoom lens on the market, along with the Sigma 300-800mm F/5.6 EX DG APO HSM that was launched in 2002 and weights almost 6kg. Certainly, the Olympus 100-400mm will be much lighter and significantly smaller.