milestone 7 of firefox 3 was released a couple weeks ago. from what i can tell, its on the home stretch to being delivered. im downloading the linux version now.
this product requirements document has interesting info.
most concerning is the "At risk" status for "Provide a simple identity management UI" and "Support OpenID"
single signon was supposed to be one of FF3's big wins. the other being the browser itself is a webserver, although i dont see mention of that on the feature list.