Oh, what is this? In addition to the previously unearthed features, the next generation iPhone's guts will have full FM transmission and reception capabilities, according to its spec sheet:
The BCM4329 includes both FM transmit and receive capabilities. FM transmit enables consumers to stream music directly from a personal media players (PMPs) or mobile phone to car stereos or home theatre systems without having to purchase special adapters or use bulky cables. FM receive is already a popular feature that enables consumers to obtain real-time traffic information as well as listen to music, news and sports broadcasts on their mobile phones.
I'm not interested in listening to radio or news—although many have been demanding this capability in iPods for ages—but I can't wait for the built-in transmission to the car stereo, as well as real-time traffic information data everywhere, independently of the 3G connectivity. [Broadcom via AppleInsider via 9to5]
Update: Apple Insider say the previous chipsets had potential FM functionality as well, but Apple's declined to switch it on.