what I find most amusing is that most of the improvements described come to 'rewrite the magnetic stripe' and 'rewrite the numbers' - and if you have accounts in different banks, you'll still need a different card for each of these.
The fact that you can now 'concentrate' several accounts on a single card is great, but it would be made useless if the card itself was secure enough to manage all your operation through a single identifier.
As an example of that, currently in Europe, with a single SIM card, you can:
- use it as a phone card in a phone booth,
- use it as a limited amount wallet: no online validation needed, the card itself stores a small amount you can debit from,
- use it to manage all your accounts from one of your bank's booth.
The only limitation, again, is that you need one card per bank.
The main use I'd see for one of these improvements is if you had several debit accounts: say, a personal one, a shared one, and a professional one, all at the same bank.
For the battery matter, considering the SIM is powered on by the reader, which still has to cater to older models, said reader should send enough juice for the card's accumulators to charge.