Originally Posted by AnemicOak
To update them you'll need to re-download the books. I don't think there's a way to know for sure, but most books I've downloaded since K4PC started supporting KF8 came as a KF8 version (still a few older mobi's and some nasty Topaz).
Darn. I guess if there's no way to know which ones have been updated with new KF8 support I'll just have to wait until my PaperWhite shows up and start reading them there.
Just re-converted an epub that I've been reading using KindleGen and it looks much nicer now! The book I'm reading has some small, italic, right justified quotes at the beginning of each chapter that look much better in KF8 format!