Well, I've just downloaded the beta of Windows Life Writer, and this is my first post with it. It works well - complete with a spelling checker. A neat feature is that WLW downloads the blog style sheet, thus real WYSIWYG!
The WLW tool is simple and easy to use and passes the Ronseal test (It does what it says on the tin).
WLW also lets you insert a map into a blog posting. Unfortunately, WLW can not upload the map to Blogger.