The Olympus OM-D E-M1 Mark II camera is now shipping and is currently in stock in the US (Focus Camera, Adorama) and in Europe (Foto Hans Keuzekamp). B&H, Adorama and Amazon should also get their shipment soon and with a price tag of $2,000 I doubt the E-M1 MII will be out of stock.
Update: Olympus issued a warning about a potential delay of the Olympus OM-D E-M1 Mark II camera because of high demand... again.
Here are the first video reviews of the camera:
https://www.youtube.com/watch?v=Zq94c-2vv0c