The Wordpress developer team tries to secure Wordpress. Hence, they deactivated the XML-RPC and the Atom API.
Without these APIs it is not possible to post to your blog using a desktop blogging software like WIndows Live Wiriter.
Thankfully they didn’t delete this API. It can be activated in Wordpress Administration (Settings –> Write).
via Frank Bültge

After a long time of inactivity, we relaunched the english Live Writer Blog.
The new Live Writer Blog is based on Wordpress instead of dasBlog. Along with this new base there are numerous of new features. You can rate the plugins we write about also the author of a post about a plugin can rate the [...]

The Live Writer Blog is online. You will find here News about the Microsoft Windows Live Writer and the reviews about new Plugins.