JVerstry - 8:22 am on Sep 12, 2013 (gmt 0)
I did it on Sept 8th (4 days ago) and resubmitted a sitemap.
Webmaster's index status is starting to show a downward trend in the number of indexed pages, but it is still high.
This morning, I am also seeing a tiny recovery in search queries for Sept 9th data, I hope it is the beginning of a bigger trend.
Yesterday (Sept 11th), I beefed up all pages with users instructions, meaning a minimum 250-300 words (prose) on all pages. Before, I had at most 100 words because I wanted to keep the layout sober and clean. These instructions can be displayed/hidden with a click on new help links. I have also removed small keyword lists I was maintaining in the footer to compensate for the lack of word content.
I have also decided to index again the 260 pages than would cover for 90-95% of my traffic. This morning, Webmaster says 661 pages have been submitted and 553 are indexed. So about 2,4% of the total number of pages on my website.