A plea to Olympus: Exposure compenastion in manual mode on the E-M5

You can forget it, you don't need it if you shoot RAW (and why wouldn't you at high ISO?)

I compared shadow recovery between ISO 3200 exposed well and ISO 400 underexposed by 3 stop. The difference was very minor. And there was almost no difference between ISO 6400 exposed well and ISO 800 underexposed by 3 stops.

You certainly won't notice any difference if Auto ISO sets ISO 800 as opposed to ISO 1600 that you could get with +1EV ISO compensation if it was available.
http://forums.dpreview.com/forums/post/42141106