Here is a recap of what happened in the search forums today, through the eyes of the Search Engine Roundtable and other search forums on the web...
As you know, Google told us they just realized that rel=next and rel=prev is no longer supported for the past year or so. Yea, I know. So now what? How do you ensure Google can find your paginated content? How do you communicate to Google a series of pages is part of a set? Mihai Aperghis asked Google's John Mueller a series of hard questions this morning in the webmaster hangout addressing this.
With all the controversy around Google just noticing they haven't supported the rel=next/prev and now trying to dig themselves out of a hole - folks are curious how Bing supports it. Frédéric Dubut from Bing said on Twitter that Bing uses them for discovery and understanding site structure but they do not use it to merge pages into a set.
Yesterday during the webmaster hangout, I noticed that the documentation on "Indicating paginated content to Google" that talks about rel=next/prev is now gone, 404ing. Also, the blog post about it from 2011 in bold reads at the top "Note: The information in this post is outdated. Rel=prev/next is not an indexing signal anymore."