There is one feature of the OM-D which I think will be revolutionary: the Live Time mode. It is a time exposure just like the "T" setting on old film cameras, in which the exposure starts with one press of the shutter release button, and does not terminate until the button is pressed a second time. With film cameras a "T" exposure was always a guessing game – who knew if the exposure in twilight should be five minutes, or twenty-five?
The OM-D eliminates the guesswork, updating the live view as the exposure progresses. When it finally looks good, you terminate it.
There is also a Live Bulb mode, just like the old "B" setting on your old Leica dial.
This should be fun.