According to Apple Insider, the upcoming iPhone 3.1 – tipped in the latest Apple firmware leak – will use the Broadcom BCM4329 wireless chip. That chip is known to support advanced power saving features, WiFi draft-n and FM receiving and transmitting, suggesting the new iPhone may be able to stream music to a car stereo.
The current iPhone 3G uses the Broadcom BCM4325, which has an FM receiver. However Apple have locked down its functionality; currently it will only receive short-range FM transmissions from the Nike+ exercise peripheral. Of course, there’s no telling whether Apple will similarly lock down the FM capabilities of the iPhone 3.1; many third-party accessory manufacturers, who already offer a broad range of FM transmitters, will likely be hoping they do.
As for the WiFi n functionality, the newer Broadcom chip supports all manner of MIMO dual-antenna signal boosting and better reception. There’s also a shared Bluetooth and WiFi receive signal path which should save power and space but not at the cost of signal strength.