Google Product Forums
Re: Almost unbelievable SERP Drops. I think i'm gonna be sick.
Crawling, indexing & ranking :
I have been told by a Googler with direct knowledge that this will likely work. His exact phrase was that high quality new links would work to balance the changed algo over time.
He did also mention that it is conceivable that some domains will have such bad link profiles that starting afresh would be better. Note he said "conceivable".