Interesting device. Small form factor. I think the key feature they bring to the table is secure boot. So you can guarantee that the image you are about to load into the device has not been tampered with. Presumably it's signed with keys that are in the device and can't be read out.
Otherwise it's just a linux host which can run standard utilities like ssh, openssh utils (so you can run a CA) perhaps a bitcoin client and store your keys securely etc.
Sounds pretty cool because it's open and inherently hackable.