The OM-D E-M10 Mark IV camera is already listed as discontinued at some stores in Japan:
The OM-D E-M10 Mark IV is currently in stock in the US at B&H Photo.
The OM-D E-M10 Mark IV was announced in August 2000:
Announced: Olympus E-M10 Mark IV camera and M.Zuiko Digital ED 100-400mm f/5.0-6.3 IS lens
Via asobinet