dasBlog support seems to be limited, although this is mostly because of dasBlog itself. I made the switch last month to using my own installation of WordPress which means that I had to also install PHP and MySQL on my Windows Server. So far, so good; the installation took me less than 15 minutes and worked on the first attempt.
Windows Live Writer has support for a number of different implementations including the new release of Windows Live Spaces, which is the new MSN Spaces.
Windows Live Writer is in the beta stage, but is very stable and has a full SDK available so you can write your add-ins. Check out my brother’s post on WLW … He has some good explanations and screenshots to go along with it.