Next gen USB is one step closer to reality with the introduction of the first USB 3.0 host controller chip for PCs. The new NEC's µPD720200 chip is backwards compatible and supports speeds of 5 Gbps. [Wired]
What will take advantage of all that speed? USB external hard drives?
eSATA already can do that... with no overhead. USB always has overhead.
You can get an external enclosure with eSATA and USB 2.0 right now... and get speed at home, and USB portability at your friend's house. For me, I'll take a hit on speed with USB 2.0 for the 1% of time I'm out of my house. And eSATA is available now.
Sometime next year, I could buy a USB 3.0 external enclosure and a USB 3.0 card for my computer... yippee! But it will run at USB 2.0 speeds on another computer, until USB 3.0 is on EVERY machine in the world. And that's a long time away.
Other uses for USB 3.0 are camcorders and digital cameras. But, it will take years before cameras get USB 3.0. And the limiting factor is really the speed of the drive inside the camcorder. Sure it will be nice to transfer HD video clips from my camcorder... but USB 3.0 isn't gonna make the 1.8" hard drive in the camcorder spin any faster. Or an SD card in a digital camera read any faster.
The jump from USB 1.1 to USB 2.0 was groundbreaking... hard drives transferred faster and memory cards from your digital camera could be copied faster. But the jump to USB 3.0 will be limited by devices and the environment.
I'm excited about the idea of a superfast USB 3.0 flash drive... but it will be years before every computer has USB 3.0 so you can use that speed on every machine.