Over the past couple of years, it has become abundantly clear that authorship will continue to play an increasingly important role in how Google determines when and how to rank some types of content in search results. Nothing is changing there, and you can expect Google to continue to look for ways to improve how it uses this signal.
Google's Matt Cutts put out a new Webmaster Help video today discussing this. Specifically, he responds to the user-submitted question:
Will Google be evaluating the use of rel="author" moving forward as more sites use the feature on generic, non-article/news pages, such as the home page or an about page?
"My brief answer is yes," begins Cutts. "I'm pretty excited about the ideas behind rel='author'. Basically, if you can move from an anonymous web to a web where you have some notion of identity and maybe even reputation of individual authors, then webspam, you kind of get a lot of benefits for free. It's harder for the spammers to hide over here in some anonymous corner."
"Now, I continue to support anonymous speech and anonymity, but at the same time, if Danny Sullivan writes something on a forum or something like that I'd like to know about that, even if the forum itself doesn't have that much PageRank or something along those lines," he continues. "It's definitely the case that it was a lot of fun to see the initial launch of rel='author'. I think we probably will take another look at what else do we need to do to turn the crank and iterate and improve how we handle rel='author'. Are there other ways that we can use that signal?"
Cutts concludes, "I do expect us to continue exploring that because if we can move to a richer, more annotated web, where we rally know...the philosophy of Google has been moving away from keywords, 'from strings towards things,' so we've had this Knowledge Graph where we start to learn about the real world entities and the real world relationships between those entities. In the same way, if you know who the real world people are who are actually writing content, that could be really useful as well, and might be able to help you improve search quality. So it's definitely something that I'm personally interested in, and I think several people in the Search Quality group continue to work on, and I think we'll continue to look at it, as far as seeing how to use rel='author' in ways that can improve the search experience."
Cutts discussed authorship in a hangout about social search back in the fall. In that, he indicated that authorship could become a weightier signal in the future. In fact, he dubbed it a "long term trend".
The moral of the story is: If you have started building reputation and credibility yet, you should probably do so. You'll also want to implement authorship markup.