That doesn't look like a NAS device to me. Unless USB2.0 is a NAS, which I never assumed it to be.
404'd, from what I'm seeing looks like a pretty good idea, I mean there are removable solutions out there but this is a pretty solid product, especially the ability to have a small solution, such as a single bay inside a current case and have the ability to switch the drives. The bigger external connections are pretty sweet lookin' too! I'd be willing to give it a shot, I can't see hard drives being worse than these friggin tapes I keep mess'n with.