I'm just testing out Windows Live Writer. A completely new tool by Microsoft, still in Beta but it works already great with dasBlog. You can also extend it with extra plugins (1). It still lacks some extra's but I already like the nice integration with dasBlog. Even the Categories are available.
Update: There are already some nice plugins available on CodePlex: Window Live Writer Plugins, Flickr4Writer and Tag4Writer.
Update 2: It seems another VISUG member also has created a plugin for Live Writer: SyntaxColor4Writer.
(1): windows live writer plugins: flickr and tagging and Write a Windows Live Writer plugin using C#.