As we were talking (http://blogoscoped.com/forum/116916.html), Blogger is going to support OpenID and other blogging platforms for comments.
In this (http://www.elventanuco.com/2007/12/blogger-abre-el-acceso-sus-comentarios.html) blogger reports (spanish blog – has a screenshot), it has support for Blogger, OpenID, AOL, AIM, LiveJournal, TypeKey, and Wordpress.
However, I cannot reproduce this with my blogger blog nor commenting other blogs.
I stick with my wordpress blog anyway :P

We installed it at Zorgloob, it (OpendID) works very well.

The other platforms use OpenID too.