I have tested BloGTK + tomboy-blogposter + gnome-blog and all of them have problems with blogger. Gnome-blog is the simplest. It is a panel applet for the gnome-panel and has a very clean, simple, and fast interface. On the other hand, BloGTK is a standalone app that is a little bulky. Neither of these programs will post titles of posts correctly (BloGTK refuses to allow a title at all and gnome-blog posts the title as part of the body of the post). Tomboy-Blogposter does post the title correctly (because it uses the new API) but does not allow for HTML (links etc...). I am therefore resigned to look for another program (I will try Scribfire next).

Edit: Gnome-Blog cannot post pictures to blogger.