When html started being 'designed' presentation and structure muddled together and there was little semantic meaning attached. This html soup was found everywhere, even big sites like yahoo and google. Later styling and content was separated, making maintenance easier and making room to introduce of semantics. And while semantic markup works well for people. It doesn't help the computer understand the syntax and semantics of the information. Only the structure and importance. Web semantics and microformats allows authors to better describe the syntax and semantics of information to help the computers better understand our information. Microformats are part of this semantic solution. They allow the addition of semantic and syntactic information to HTML.
As a transition to fully semantic code would be a difficult and lenghty process. There are many different microformats to handle different types of information, such as hCard for people, and hCalendar for events and dates. The use of microformats is invisible to the human user. However, they greatly improve the computers' ability to understand information. Microformats are implemented in a few clients. The operator extension for firefox will allow automatic parsing and retrieval for microformats. Microformats also enhance usability for people with accessibility issues. Guillermo Nuñez then presented a prototype browser / browser plugin that creates additional accessibility links for microformat data, such as adding 'call' button to make a skype call from the browser. In addition to this a helper for creating microformats.
As a side note this presentation was done in spanish, and my hat is off to the translation people as it was a very well done and seamless experience for a non spanish speaker.