Sony's put out a ninja firmware update, 2.42. It took eons to download, and it seems to be a meaty update. We can't yet decipher what exactly it does (wasn't the XMB's "Turn-Off System" button there since 2.40), so we imagine it's loads of back-end stuff. And according to the PlayStation.Blog, that's exactly what it does:
This update improves the playback quality of some PLAYSTATION 3 and PlayStation format software.
Not so sexy, but hey. Not every firmware update can be sexy. That's just the way it is.