I have to say that a new update L lens within one or two year range of the current model is too fast. I just ordered Mark II yesterday and see this rumor. Of course I can sell it when a new model announced like I am selling my mark I right now. But if I have to do it within 2 years, of course I do not feel good. The good thing is it is only a rumor. We never know when until it ship. I know businessman are way smarter than I am. If you have to take pictures, buy the current model now.
