Wanted: PyBlosxom plugin to bake CSS styles into the RSS feed, i.e. replace things like <span style="keyword"> in the main blog pages with things like <span style="color: #ff7700"> in the RSS.
Also wanted: a spam-resistant comments plugin. (Maybe some/all of them are? I was always afraid to try.) And a tags plugin (categories are too limiting). And useful page titles. And a pony.
Update: Laurence Rowe and Alexander Artemenko suggested I check out cssutils. Alexander also pointed out that a similar question was asked on stackoverflow. Peter Bengtsson recently posted a similar tool built with lxml and regexps. Meanwhile, I took the plunge and installed a comments plugin, and even somehow managed not to get drowned in spam.