Matters

Developers Wiki - MicroFormats
"microformats are:
a way of thinking about data
design principles for formats
adapted to current behaviors and usage patterns ("Pave the cow paths." - Adam Rifkin)
highly correlated with semantic XHTML, AKA the real world semantics, AKA lowercase semantic web, AKA lossless XHTML
described by Tantek's recent presentation at SXSW: The Elements of Meaningful XHTML
a set of simple open data format standards that many (including Technorati) are actively developing and implementing for more/better structured blogging and web microcontent publishing in general.
"An evolutionary revolution" - Ryan King
all the above. "