I'm kicking the tires on Brad Rhine's Frequency desktop blog posting application. Currently, I'm liking it better than w.bloggar which, as far as I can tell, is the cream of the current crop.
Minor nit, Frequency needs a refresh button on the edit posts list.
Update There's a menu selection, Posts : Refresh List, and key combo, Ctrl-R, to take care of the above nit. Thanks to Brad Rhine