I've started taking a look at a new open source publishing platform (i.e. blogging platform) called Melody (http://openmelody.org/). The reason, I think, that Melody is most exciting (besides being another open source blogform like WordPress) is that Melody wants to be completely open: not just in source, but in community effort. In the words of Byrne Reese, one of the creators of Melody, "A core value of the Open Melody Software Group is transparency, or a promise to develop and discuss the product out in the open so that everyone has an equal chance to participate, audit our process, influence our roadmap and share in the excitement of building a product together." Melody is currently in the alpha release stage, and I may decide that I want to download it and try to run a server on my desktop just to test it. Regardless, I look forward to its full release, and I hope that the Open Melody team looks into getting a domain for running the first blog server using Melody at that time.
UPDATE: The Open Melody team will be running a blog server on their site. In a message to me on Twitter: "We plan on running Melody on openmelody.org as soon as it's stable. I'd say once it hits beta, we'll unleash it on the site." I'm excited! :)
CORRECTION: We had a confusion of terminology about "blog server." Open Melody will not be running a hosted environment on their own site. Hopefully someone will catch on though. Thanks, Dan!