Olympus Japan announced that the new OM-D E-M1 Mark II MFT camera and accessories will start shipping on December 22. The US shipping date is currently listed as December 12th at B&H, Adorama and Amazon:
Update: I received some additional information that the Olympus OM-D E-M1 Mark II camera will start shipping this week in the US and dealers can start selling it on December 12th.