Couple Points
@Calum
Firewire connectors are backward compatible from 3.2 Gbps to 800 Mbps. (The 50 Mbps to 400 Mbps connectors are different. [And yes, Firewire started back in 1990 at 50 Mbps.])
In quantity Firewire chipsets are not that much more expensive than USB chipsets but in huge quantities (millions) even a few pennies count. The disparity comes when you want to connect two peripherals to each other. Want to connect a USB 3.0 Super Speed camera to your USB 3.0 Super Speed HDTV? Better put that home theater PC in between to control the connection. That changes the entire pricing equation. With Firewire 3.2 Gbps on each item (camera and TV) you'd just run a cable between the two and go for it.
Firewire for 1.6 Gbps and 3.2 Gbps over copper using the existing 1394b (800 Mbps over copper) connectors has been approved for well over a year. It is not "proposed". Additionally, 1.6 & 3.2 Gbps over fiber has been approved for several years (approved about the same time as 800 Mbps over copper, IIRC). To my knowledge no one is shipping any systems or peripherals with 3.2 Gbps over copper Firewire, but the standard does exist.
General thoughts...
Even with the overhead and CPU leeching of USB 3.0 Super Speed it is still probably faster, on average, even for streaming media than Firewire 3.2 Gbps. While I have not done any detailed calculations of the 10b8 overhead and such it is difficult to believe that the overhead and latencies of 5 Gbps USB will take the useful bandwidth below 3.2 Gbps.
If USB 3.0 catches on, as it is likely to, then Firewire will go the way of PATA.
Biting the hand that feeds IT
