Matt from WordPress.com about the Windows Live Writer:

It’s a little known fact, but deep within the labyrinths of Microsoft there is a team of rogue ninjas making a fantastic Windows blogging client.

If you compare the capabilities of the last Windows Live Writer release and WordPress 2.1 with the new Windows Live Writer and WordPress 2.2 you notice that much work was done.

• Windows Live Writer vs. WordPress
  If you are using WordPress and Windows Live Writer together and you are having problems, maybe these solutions from WordPress.org can help you. Image uploading fails Posting fails for some blogs that don’t use UTF-8, ISO-8859-1, or ......


• Windows Live Writer WordPress and the XMLRPC Issue
  Sometimes when you try to set up a new blog account with the Windows Live Writer the installation process might be interrupted by an error message: Invalid Server Response – The response to the blogger.getUsersBlogs method ......


• WordPress: Bad Behavior plugin doesn’t like Windows Live Writer
  Description: Blogs with the Bad Behavior plugin installed cannot be used with Windows Live Writer. Attempting to add the blog to Windows Live Writer results in a “403 (Forbidden)” error dialog. Reason and Solution: See this ......