Boilerpipe is by far the best tool for this that I've ever found (http://code.google.com/p/boilerpipe/). I'd be interested to hear if he is using something better, but I'd be surprised if he is.
I think this is a great idea and very similar to a lot of stuff I have worked on recently. It's cool to see so much interest in these text-related services.
Thanks for that link - exactly what I was looking for
btw I know that at Techmeme, Gabe spent years perfecting his story parsing for the 50k+ sites he tracks. Even something that would seem simple such as parsing the date of a story from a webpage has a ridiculous number of permutations that you have to grep for.
I don't think it's quite as good as what he's doing though. He has the title and date specifically pulled out and he doesn't have any extra text included. I think he manually handles CNN. If I try a HuffPost feed it doesn't work at all.
Yea, I'd be curious to see exactly what he's doing. I can only guess there is a heuristic which results in a lot of failed feed processing noticed on here (I know it's just a weekend project :)) that doesn't generalize well. Boilerpipe, in my experience, works very well on almost all news/blog type content. Finding the date in the first few sentences and the title are extra heuristics that can be added later.
EDIT: The date and title are in the RSS feed already! No further analysis needed.