Here is a link to new firmware:
Olympus - E-M1 - System Cameras ; Micro 4/3 Cameras
It has a 0 sec delay option for an effective electronic shutter up to 1/320 second.
However I just installed it, and set it in the menu, but it still 'clicks' the shutter when shooting, so it doesn't actually seem to work even though it is selected in the menu. Has anyone else tried this out? If so, does it work for you.
I set it to 1/4 sec, and you can clearly hear the first and second click before and after. hmmmm.
BTW shutter blur on the E-M1 also on my E-M5 before have been very frustrating for me, so I was happy when I saw this update, but so far I haven't figured out to actually use it.