Sony has introduced a mandatory PlayStation 3 System Software Update (version 3.30, if you're keeping track) adding several new features, such as changes to the trophy system and preparations for 3D gaming.
While Sony hasn't released any 3D titles yet, games with the extradimensional goodness are due as early as June. In that same timeframe, Sony will launch its 3D Bravia HDTVs, so it seems the 3D craze could pick up steam over this summer into the holiday season.
As for the trophy enhancements, you should now be able to sort trophy lists by any category, such as the date obtained or trophy value. Version 3.30 also includes updated Flash support for the PS3 browser, the addition of PC remote play (for upcoming VAIO systems), and tweaks like a smaller RAM footprint for the firmware, which will allow developers to use more memory in future games.