The folks over at mozilla.org have been busy:
New Firefox Release 1.0PR includes Live Bookmarks, which creates a bookmarks folder out of an RSS feed, and a really slick interface for finding text in a page. It does disable some older extensions, though, so look out. My main gripe is the loss of the bookmarks synchronizer. I hope the author is working on a new version.
New Thunderbird Release 0.8 includes the ability to have a single inbox for all POP3 subscriptions (that was always my main gripe), and sports an integrated RSS reader.
New Mozilla Release 1.7.3 includes security fixes.