If this does what I think it does, its a superb idea and about time someone released it!
Basically you plug in the USB stick to your PS3 (or any other device with USB) and it registers on said device as a mass storage drive (i.e. pretends it's an external HDD). But it isn't actually a mass storage device, instead it links up (completely indenedantly of the machine it is plugged into) to drives on your PC / NAS device etc.
It's a superb idea, and a great way to have a large NAS solution that can still work with the PS3!
Will definitely be looking for more info on this!