There have been a couple discussions on changing to https: for you sites, the last one being about WordPress moving forward with requiring it for full functionality sometime in 2017.
However this is a much bigger deal. Google has decided that passwords are considered "secure information" so any site that uses passwords to login or access data will show a security warning if the visitor is using Chrome.
You have to believe that the ranking hit for sites getting the warning is going to be stronger as well. It would make no sense for Chrome to give out security warnings for a site and then rank that site high in the serps.
This morning, Google began sending out notices through the Google Search Console to websites that have login and password fields on pages that are not over HTTPS. The notification says nonsecure Collection of Passwords will trigger warnings in Chrome 56 for domain.com.
Chrome 56 in January will issue a security warning for web pages that have these login fields without serving them on a page that is over HTTPS. The message reads:
Beginning in January 2017, Chrome (version 56 and later) will mark pages that collect passwords or credit card details as “Not Secure” unless the pages are served over HTTPS.
The following URLs include input fields for passwords or credit card details that will trigger the new Chrome warning. Review these examples to see where these warnings will appear, and so you can take action to help protect users’ data. The list is not exhaustive.
Google also posted about this on Google+ and wrote:
From the end of January with Chrome 56, Chrome will mark HTTP sites that collect passwords or credit cards as non-secure. Enabling HTTPS on your whole site is important, but if your site collects passwords, payment info, or any other personal information, it’s critical to use HTTPS. Without HTTPS, bad actors can steal this confidential data..
Google Search Console warns of nonsecure collection of passwords with upcoming Chrome release