hyphenator I could take a look at, because then the hyphenation simply runs with JavaScript in the browser. It's only interesting for the websites themselves anyway, feed readers have to render themselves.
Update: yeah, looks good. Now I can look at my homepage again without getting pimples, and the integration was very simple with their custom package builder - go through a few checkboxes, build an optimized download version of the library and include it in the head of the blog. As a class, I simply used entry-content, which means that all posts (and only those) are provided with hyphenation. And since it's client-side, it doesn't affect the feed or any other internal paths.