Among the uses already pointed out, you can use the articulated screen while looking through the evf to choose your focus point with your finger. It's a touch screen (obviously) so it becomes a nice adjunct to the control buttons. And the camera has an eye sensor that will switch between EVF and LCD when you approach/withdraw from the vicinity of the evf.
The bar has been raised, and I think you'll see this technology increasingly make it into the DSLR segment (even as mirrorless eats away at the segment). Canon 60D has had an articulating screen for some time...
Of that dpreview said:
"However this increased reliance on the rear screen hints that the 60D is trying to stretch beyond the classic DSLR use pattern. And for video shooters the large, detailed and articulated LCD will more than outweigh the tweaks made to viewfinder shooting. Sadly the contrast detection autofocus is still slow enough to reduce the usefulness of the articulated screen for handheld stills shooting, but tripod users and shooters of static subjects should appreciate it."
The GH3 has extremely fast AF... a rumored Sony sensor... and a magnesium alloy body that promises to be quite a bit nicer than the build on the GH2...
At the end of the day this is just an example of where this is showing up. How the market has and will respond seems pretty clear...
woof!