If you're expecting Canon and Nikon to suddenly dump their entire OVF range of models I think you're in for a shock. They won't and even if they play around with EVF's at the lower end (and nobody would be shocked if they did) certainly at the enthusiast and up range it would be very unlikely that they would stop users having a choice of OVF models. In effect Sony have dumped their OVF users in one fowl swoop by stopping production of the FF DSLR bodies and A580 model. That I think is a mistake, to deny a customer a choice is clearly flawed. If you dig around on DPR there is a thread right now about "do you want an EVF" I see some well known former Sony users who are now Nikon customers because of this.
I think Barry may or may not be right in pointing out that Sony are either wrong or too quick in dropping OVF models in both APS-C and FF ranges.
Clearly Sony are determined to continue with FF cameras or they would not release the new 500mm F4 lens and possibly plan upgrades to their smaller SSM/G lenses as well as talking about FF camera releases.
Either Sony are confused or their technical people must think that within a short time they can release cameras with
Superior sensor - a reasonable assumption. Probably already a fact.
Superior EVF eliminating lag and the lack of highlight/shadow resolution.
Maybe they think that if their new EVF offering can match OVF under normal lighting conditions and be superior in darker shooting conditions they can "steal a match" on NIK/CAN. Such an EVF might also be cheaper to make and provide for faster shooting as a bonus.
Maybe they see themselves actually having a competitive advantage come 2013 and hence the reason they are also upgrading/extending their SSM/G lens portfolio and perhaps adding additional Zeiss glass. That belief could explain why they appear to be concentrating all their technical development on SLT and NEX products.
If they don't think along these lines I am at a loss to figure out what they are thinking. The idea that professionals are against EVF per se surely is wrong as many of them use video and EVF. If a Sony camera came on the market with a superior EVF and still/video capability to beat allcomers there would be room for Sony. Sony are betting on new technology as a way to get their desired market position and frankly I for one believe they are doing the right thing because I cannot see how they can capture a decent market share by continuing to invest in OVF DSLR cameras. Simple as that.