When we search on the Internet these days, we expect to be given a list of potential sites which will hold the answers we seek, be that a product, a specific data set, an answer to a question and so on. It is then down to us to seek the answers or research further until we find them. However, Google appears to be about to up the ante and head more towards providing direct answers to questions rather than links to sites where that answer may reside.
Potentially, this is huge.
For Google, it may mean that anywhere between 10 and 20% of all search queries could be answered directly within Google search, rather than on third party websites that currently pop up in the organic search results. This could have a drastic effect on traffic to websites, especially those who have not looked beyond the search engines to create broad spectrum marketing campaigns. Having all your eggs in one basket is never a good idea, and this change at Google may well prove it to those who have pitched everything at SEO and little to nothing at social media, mobile, PPC, article marketing, forum marketing, etc etc.
Optimising (SEO) may need to change in order to be more than just keyword rich, but also to be 'answer rich' ie to provide the answers that Google offers to searchers. Therefore, within the copy and content of a site, it may be necessary for the SEO expert to try to envisage more clearly exactly what answers are likely to be sought, and hence, the question(s) that may be in the mind of the searcher when entering the query.
On the plus side, trusted sites which continually create unique, quality content should have an easier time of it than those sites which duplicate other sources. Relevancy, creating author tags, correct labelling of content (as is required for Google shopping for instance), strong reasons for a user to stay within a site rather than return to Google, regular competitive analysis, and a need to co-ordinate marketing strategies towards Google all look likely to be required to ensure at least a modicum of success with Google's semantic search.
There are likely to be some downsides in this ambitious proposal. There have been plenty of occasions where the algorithms have thrown up what could be considered irrelevant results; be these the type of results that Panda was introduced to eliminate, or inappropriate adverts, and Google will need to stick to facts first and produce consistently accurate results in that sphere (as it does now for simple search queries such as measurement conversions) or it could come under fire for losing yet more relevancy.
If you thought that the search engines' algorithms were hard enough to optimise for, wait until you are up against AI (artificial intelligence) deciding what should show in the SERPs! Especially if/when the semantic search moves beyond factual e.g when is the full moon in April 2012? to the opinionated: e.g "Is SEO necessary?"