Typo – Ruby on Rails, not as fully-featured but growing. Drupal – Very cool looking, lots of plug-ins and features. WordPress – Lots of people are moving this way, but I hear some complaints as well. I love the wealth of plug-ins.
Community Server is pretty much out of the running in my mind, I don’t like the bloat-factor (all I need is a blog) and I don’t like the license it’s released under. (some of my favorite software is the result of “code forking or derivative versions”)
I will be trying each of these out over the next couple weeks and try to make a decision, right now I am leaning towards Typo.