The 400 is a different architecture with a different network topology, very little overhead. In reading the article and digging a bit more on USB 3.0, it look like they're going to try to take a couple of features from Firewire. Getting it to go peer-to-peer as I've read is going to be a hack.
It's just the facts: USB was designed to replace the old slow serial and parallel ports, so its architecture was designed for enough speed to run devices you'd have plugged into those, up to 12 Mb/s. Firewire was designed to replace SCSI for high-speed external devices, such as scanners and hard drives, so was designed for high sustained throughput from the beginning.
And I wonder whether they'll finally put a decent amount of power through USB.
I'm just reporting what I've done and seen. This isn't something I've read, something someone else said, or a lopsided unequal test on a stacked deck.
Both external drives are based off of 2.5" drives. Different manufacturers. 320GB firewire vs 500GB USB 2.0. Same sized Intel MacBook image. Same file copied to both drives from the same server. Same version of NetBoot/NetRestore off a Mac OS 10.5 partition on each drive.
Takes about a half hour on the USB and 45 minutes on the firewire.
Could be a Mac driver thing. Could be that there's a hardware glitch with the 320 drive. Could be a lot of things.
But now look at how many desktops, servers, and laptops have USB 2.0 vs. 1394 ports... The market speaks for itself.