yeah unfortunatly
both yahoo and blogger have just become openid providers
they do not seem to have any plans to let their users move grom id/password on their own sites to openid
{openid only recieves real support from sites allowing login credentials to be associated with an openid {or even a few} thus giving the users the choice to only have to remember the one set of credentials for all sites they use openid instead of username / passwoed}
more openid providers are not really needed, and yahoo's encoraging of people to use a login with yahoo on their sites runs contrary to the entire point of openid