I just have been informed that Metabones will launch the new Speed Booster adapter for MFT in April and not in March as previously reported on their website. They are still not sure what kind of lenses will supported yet but I have been told the adapters will be manually only (no electronic support). Price may be around $399 (still not final decision yet).
Officially the Nikon, Leica R, Contax C/Y, Contarex, ALPA and Rollei lenses are on roadmap plus OM lens adapter may come too. I am pushing Metabones to make an OM adapter as some of these lenses are owned by many 43rumors readers and by me
List of OM prime lenses. Click on the link to check the price and auctions on eBay: 21mm f/2.0 and 21mm f/3.5 lens, 24mm f/2.0 and 24mm f/2.8 and 24mm f/3.5 shift lens, 28mm f/2.0 and 28mm f/2.8 and 28mm f/3.5 lens, 35mm f/2.0 and 35mm f/2.8 and 35mm f/2.8 shift lens, 40mm f/2.0 lens, 50mm f/1.2 and 50mm f/1.4 and 50mm f/1.8 and 50mm f/2.0 macro and 50mm f/3.5 lens, 55mm f/3.5 macro lens, 85mm f/2.0 lens, 90mm f/2.0 macro lens, 100mm f/2.0 and 100mm f/2.8 lens, 135mm f/2.8 and 135mm f/3.5 lens, 180mm f/2.0 and 180mm f/2.8 lens, 200mm f/4.0 and 200mm f/5.0 lens, 250mm f/2.0 lens, 300mm f/4.5 lens, 350mm f/2.8 lens,, 400mm f/6.4 lens, 500mm f/8.0 lens, 600mm f/6.6 lens, 1000mm f/11 lens.