New 300mm f/4 IS L II likely

May take a while to show up at your local dealer. But my guess is that this lens will actually hit the shelves sooner than later:

http://www.canonrumors.com/2012/08/patent-canon-ef-300-f4l-is-ii/#more-11039

Great news if its a true upgrade. Would make shooting 300mm f/4 a feasible alternative to slugging around the 300 f/2.8 IS L.