The new 300mm PRO lens is in Stock and shipping today(!) at FocusCamera (Click here).
And the lens just got reviewed by ePhotozine:
Considered against what users of other marques might pay, the cost of the Olympus 300mm f/4 does seem to be very reasonable. We can add to that its compact size, relatively light weight and excellent ergonomics. Quality is superb. All in all, a lot of thought and skill has gone into this lens and it is certain to find favour amongst Olympus MFT sports and wildlife photographers. The fact that close focusing brings other subjects into range is an added bonus.