In this late 2014, I can say boldly say SEO has changed and schema.org markup is playing a super role for seo.
The days have gone when we used to optimize keywords with lots of anchored backlinks, make high keyword density etc.
Now SEO means serving better user experience. We have to make our blog semantic so anything to everything can understand it easily.
We can make blogs user friendly with rich contents, proper formatting, easy navigation etc. But what if we need to make it friendly for search engine crawlers?
So here comes schema.
Schema microdata or rich snippet now can boost up your seo. Do you know how to add schema.org markup to wordpress site? You should check this guide.