I now have Classifier4J and
nntp//rss working together to do Bayesian classification of RSS feeds.
There are a few things still to work out (perfomance and usability to name two), but I'm pretty pleased with it, since it
was something I whipped up in a couple of hours. AFAIK it is the first Bayesian/RSS thing that has got far enough to have a screenshot…

(Updated to fix link to image)