I'm surprised at all the "I don't getz it ..." posts
I'm going crazy with all the cameras I have. A S100 which I always have. A Fuji X100 for when I want good pictures and need to go light and unobtrusive. A 5DMKII with a load of the best lenses and 600 flashes and gear for when I'm serious. A G12 as my sons camera, another P&S for doing short videos on vacation, my wife's camera ... (we are a photography family on vacation)
You know the hardest part? Managing all the batteries and chargers. I have a big pelican case mostly dedicated to juice. And keeping all those charged can be a mess, spend half my time running around keeping track of what is drained.
If the IQ is any good this is a dream lens for a small light setup. The 5DMKII isn't that big or heavy of a body, the weight, size and obtrusiveness is all in the lens. If they keep it up and have a series of pancakes I can ditch the Fuji and probably the S100. I am all over it