To search engine optimization some current and news trends show up, which of course at least in part are influenced or initiated by Google. The importance of seo is shown by a study stating that organic search results have grown about 20% during the last year.
Regarding Google not just trends but needs are coming up. At first there is the mobile compatibility aka responsive design to make websites readable on mobile devices. Currently Google is sending out tips via Google Webmaster Tools to teach web designers how to build mobile compatible websites.
The second trend is both general and again forced by Google. It concerns the optimization and preparation to make app content readable to search engine robots. Optimizing entries at app directories has become a discipline itself by the way and new apps enable new ways to search on mobile devices as well (s.a. Search Engine searches within Mobile Apps at the eMedia blog). Now Google has launched an interface to index the content within apps, which is described at the App Indexing homepage. This initiative is aimed to avoid redundancy and to provide optimized content to searchers either available on the web or within apps. There is at least the assumption, that app content might appear in search results in the future.
New ranking factors to search results on the web are expected as well contempling the intention of the study Knowledge-Based Trust: Estimating the Trustworthiness of Web Sources. According to this study Google may prefer hard facts opposed to soft facts like the often discussed social signals. The study describes a process for evaluating the content by facts mentioned within various websites. The procedure extracts the hard facts and will favor the site, which contains most of the related hard facts being found.
That these trends being all related to organic search results are of importance does show the last study. According to an article by Search Engine Watch the last year has seen a „growth explosion“ for „natural search“, which led to an increase of traffic to websites by 20% on average: Natural Search’s Growth Explosion, and What It Means for SEO in 2015.