I generally try not to post negative commentary, but I think there's an obvious point being missed.  Even assuming this device is made perfectly, no bugs, ships on time, performs better then expected, is cheaper than projected, and looks cooler then cool... It's still going to fail.

Purchasing a separate device to use for payments (in addition to smartphone, WALLET/PURSE, ipad/tablet, etc...) is a D.O.A. concept for all but a few of us nerds.

Why would I carry around ANOTHER single-purpose device?  The money/time/energy would be better spent integrating this concept into NFC/Bluetooth smartphone transactions.  See how many smartphones around the world are already being used for micropayments.  If you could one-up them by adding paypal, dwolla, btc, etc, you might have a viable business model.

I do think its a cool idea in a geek-cred sort of way - but global adoption? C'mon.  Even if BTC became the dominant worldwide currency, you could still make a P.O.S. purchase with a QR code of your BTC address using your smartphone; or some other method using existing tech.

'Who is picking up the check for lunch today?'
'Not me, I forgot to charge my wallet!'

Sorry, but -1.