iPhone developer extraordinaire Erica Sadun over at Ars reveals that Apple has expanded on the iPhone SDK samples, and with some pretty nifty new stuff.
While I can't claim to understand it, included in the update is aurioTouch and oalTouch for scilloscope and positional audio, Accessory and TouchCells which (apparently!) give greater options in tables and cells, and URLCache and Reflection which focus on Web-based data and image reflections respectively.
The iPhone Reference Library is an amazing resource for developers. It offers access to sample code, guides, and release notes. The new items I listed here augment Apple's already rich iPhone sample code suite. Make a habit of stopping by the library page; Apple will often add new items there without announcement.
Check it out!