I've been tinkering with this site for a week or so now. So far, I'm liking Pelican, though the default configuration makes a few assumptions that conflict with microblogging. The biggest of these is the requirement that every post has a title.
Thankfully, you can provide a "default" title, and it the system seems perfectly happy to accept None. In a few places, this gets interpolated as the literal string "None", which... not the best. I'm still working around this.