ichthyous - 4:06 am on Feb 22, 2013 (gmt 0)
My own site dropping 70+ pages is clearly some sort of penalty, but nothing is obvious or flagged in WMT (or applies in any other search engine).
I think there is no such thing as "recovery" from this. Google SERPS as a marketing tool is history.
Wilberforce I think you are right. I've got no red flags, no warnings, no sign of any penalty from Google at all. But my top ranking pages dropped about as much as yours. It's been a slide straight down for the last few months until I've lost half of my traffic. Now it seems that only sites with massive social media presence and plenty of authorship cred are making it. That's a heck of a lot harder to attain than a strong backlink profile....possible but much more work.