Having recently been using a Nex 6, I am actually quite taken by the EVF.
It has diopter adjustment (so better than lcd only).
It shows the final image - i.e., as you adjust shooting parameters you see the results in the viewfinder, instead of trying to interpret a histogram of a jpg processed thumbnail of your raw image.
The ability to use magnification and focus peaking to confirm very precise focus is amazing, for macro or even portrait the accuracy is unparalleled and effortless.
The only bummer is that Sony's image processing is no where as perfected as Pentax. In my experience, the K5IIs has much much better high ISO performance than the Sony even though they both use Sony 16MP CMOS sensors. OTH, the other day I was using the K5 and I tweaked the manual focus ring and waited and waited and it took me about 30 seconds before I realized that there would be no magnification or peaking :-(
Disruption does not come from better products it comes from cheaper products that are just good enough and technology that improves rapidly (you know the book).
And I do think that the relentless push for profit in a shrinking market will force the big players to move to EVF's to protect their margins on all but the highest end products. Don't get me wrong OVF's like film are better but will ultimately become niche products.
P.S. Has anyone noticed how quiet Adam has been..? Probably playing with his preview K3...!!