What I get from the video is that it stores the wallet - a set of public and private keys for your addresses, along with a list of transactions to/from those addresses - and signs transactions.
Bitcoin clients will implement support for reading the list of transactions to/from your addresses to figure out how much money you have. They will also implement support for using the device to sign transactions, so the private keys never touch your computer, and therefore a compromised computer cannot steal bitcoins without the device prompting the user to confirm the transaction.
As the device is a single-purpose computer, likely running the absolute minimum code necessary to implement transaction signing, it should be significantly more secure than your PC just there. And you can easily physically secure it in any way you want, whether that's carrying it around with you at all times or locking it in a safe. Anything over that is a bonus, in my eyes.
I do not currently use Bitcoins, at least partially due to security concerns, but with this, I would be very interested.
Bitcoin clients will implement support for reading the list of transactions to/from your addresses to figure out how much money you have. They will also implement support for using the device to sign transactions, so the private keys never touch your computer, and therefore a compromised computer cannot steal bitcoins without the device prompting the user to confirm the transaction.
As the device is a single-purpose computer, likely running the absolute minimum code necessary to implement transaction signing, it should be significantly more secure than your PC just there. And you can easily physically secure it in any way you want, whether that's carrying it around with you at all times or locking it in a safe. Anything over that is a bonus, in my eyes.
I do not currently use Bitcoins, at least partially due to security concerns, but with this, I would be very interested.