I'm currently trying to setup a wordpress blog and I would like for users of my mediawiki site to be able to log in using their existing credentials.
I've considered setting both up to use LDAP but I'm not sure how to migrate the information from mediawiki into an LDAP server.
OpenID is also something that I've considered, but I don't think I can restrict authentication on the wordpress site to a specific OpenID provider (the wiki).