Check out if your homepage displays on SERPs after searching site:url. Also, check out your keyword rankings, if they decrease dramatically, then...
Completely agree with you, PR will disappear from Google toolbar sooner or later.
EMD will rank as long as the site gets good content on it. The Google EMD update only punish the sites that rank ONLY by EMD, but with rubbish...
I don't think social signals would influence SEO that much, it's too easy to game. But contextual backlinks, well planned and executed, could work...
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