Microsoft has done a stellar job on Windows Live Writer. Even at beta it already supports (out of the box, no less!) a vast number of blogging engines, including dasBlog. It also supports a blog autodiscovery feature called RSD, which according to Omar will be featured in the upcoming dasBlog 1.9.
The draft feature is simply awesome: open up Writer, start typing and you never have to worry about your text going to hell (there is also an autosave feature). The WYSIWYG editor is extremely robust, lets you edit your posts using your own blog's stylesheet and has excellent picture embedding features. Although I could easily go into HTML editing mode and edit the HTML directly, I no longer see any point doing it, which saves a hell of a lot of hassle and time!
Never a sucker for web applications (AJAX or otherwise), this is a positive boon for me. Good job, Microsofties!