Which microformats should my blog implement?

Or mi开发者_JAVA百科crodata, RDF(a) or others.

'entities' a blog has would include posts, comments, taxonomies and users.

For posts I found BlogPosting and hAtom, which is a draft spec.

hCard and rel="tag" come to mind for users and taxonomies, but what do you think?

Big discussion in the community about this specific topic. I would go for schema.org - Bing's, Google's and yahoo's recent schema proposal. That is (quoting them):

This site provides a collection of schemas, i.e., html tags, that webmasters can use to markup their pages in ways recognized by major search providers.

... see BlogPosting for their specific schema for blog postings. And they also provide a mapping data model to use RDFa ... see this other one

More RDFa related, there is a port of schema.org by the Linked Data comunity RDFa using URIs here, quoting again ...

This site is a complementary effort by people from the Linked Data community to express the terms provided by the Schema.org consortium in RDF. We currently provide static RDFS documents of the Schema.org terms in the formats listed below - and yes, we're heavily working on more ;)

Which one to use ? As I said, there's a big discussion going on right now around this issue.