I got some additional info on the new Olympus 150-400mm f/4.0 PRO lens that will be announced with the E-M1X in January:
1) The lens has an integrated 1,25x converter
2) The lens has in lens 5 axis stabilization
3) Olympus will also launch a new 2x converter for this lens
I hope the price of this lens isn’t too high. I think this is a lens many wildlife shooters are dreaming to buy!