Not even 24-hours into it, SEOs and Webmasters are already blaming their poor rankings directly on their HTTPS migration.
A Google Webmaster Help thread has one SEO who said "Moved from HTTP to HTTPS, now SEO is in the ditch."
We followed the instructions to the tee. Straight 301 redirects from http to https, appropriate canonicals on all pages referencing https, and SEO has seemingly started from scratch - used to be in position 1 for a variety of important keywords ("skateboards") and searches, now they're beyond page 10.
But if you look closely, the HTTPS switch over had nothing at all to do with the traffic decline. It looks like they were hit back in July 13th to 20th time frame, at least according to SearchMetrics. So this webmaster is quick to blame the site move to HTTPS, which he just did yesterday.
I've been tracking the traffic to rustybrick.com, which I migrated to HTTPS yesterday morning around 10am EDT and there has been no signs of any traffic changes from Google organic, as of yet. Of course it is way too early to tell at this point, both in terms of a negative impact or long term positive impact.
Some people are so quick to blame. :)
Forum discussion at Google Webmaster Help.