How is USB 2.0 different to IEEE 1394?
USB was initially adopted by mainly low and medium speed PC peripherals, while IEEE 1394 was favored by AV devices requiring faster data transfer. Due to reasons of cost-effectiveness, it is unlikely that USB 2.0's high-Speed mode will be adopted for low speed USB devices. Such devices may, however, become wireless with technologies such as Bluetooth. For printers, scanners, storage devices, and other peripherals requiring faster data transfer, there may be some competition between USB 2.0 and IEEE 1394, but as far as PC peripherals are concerned, USB 2.0 is expected to become the mainstream interface. Since USB 2.0 is compatible with previous specifications, a USB 2.0 device can be used as a USB 1.1 device if the host PC does not support USB 2.0. This provides a huge advantage for USB 2.0, as the USB interface is provided on almost every PC, while the IEEE 1394 interface is not nearly as popular. On the other hand, USB 2.0 is not suited for directly linking one peripheral device to another, as it requires a host device to establish a bus connection. It will be up to the manufacturer to select the interface best suited for the device. For example, printers in the broad sense will probably be equipped with USB 2.0, while those capable of connecting directly with AV equipment may also come with an IEEE 1394 interface.

 

USB Standard IEEE1394 Option