AS a proof-of-concept, this thing is pretty interesting, though its specs are pretty low - Kabini APU, single module SODIMM and only a 32GB SSD. That said, it's a full PC that's about the same size as an ODD and has a docking station that's not much bigger. That fact that it's also upgradeable on the mSATA side is really what sets this out from other small PCs.
The docks will be sold as an accessory through Amazon on release, it seems. So you can have multiple docking stations and only one PC. The major dowsside, though, is that if you lose it, or it gets stolen, then you're SOL.