Well, I just unpacked my new EX-1 and... the viewfinder (EVF) she doesn't work. Went into the LCD/VF menu and set EVF POWER to ON just to make sure it wasn't an LCD panel switching issue. No dice. LCD panel works BTW. Before I launch my rocket attack I thought I'd check with the oracle here to make sure there's nothing untried (other than my 30-yr old rubber hammer).
"With the factory setting, the EVF is turned on when the LCD monitor is in its parked position or is rotated to face the subject. You can change the setting so that the EVF is always on regardless of the status of the LCD monitor, using EVF (page 103) of the LCD/VF SET menu. Change the "POWER" setting from "AUTO" to "ON"."
That's about the only thing that controls the EVF. You could try doing the "Reset All" thing in the EX menu or take the main battery off and then pull the memory battery too, just to see if that will change anything. Otherwise you'd better get out that rubber hammer.