Are there any compelling reasons to put money into a Google Wallet account to spend? If the only way to put money in is to have a bank account to transfer from, presumably you'd already have a debit card from that bank.
Theoretically it's acting as a layer of security on top of your real debit card. If someone clones your debit card your bank account is directly accessible. If someone clones your Google Wallet debit card, it's a bad situation but not terrible. Of course Google probably won't have the customer service manpower available to deal with such a situation (or you'll end up in email hell) so you're likely still fucked. It's better to just get a credit card.
That's how the NFC app works, but not how the plastic card works. It can only spend money already sitting in your Wallet balance, funded in advance. You can't overspend that balance and automatically charge a linked card.
The idea is that if someone sends you money via Gmail, you can withdraw it at an ATM rather than waiting for an ACH transfer to your bank account. In fact, I don't think you ever even need a bank account, if you choose to use the card to get at your money.
As is PayPal with their debit card. I wouldn't say this is amazingly new or revolutionary, it's just something you can choose to use if it works with your workflow. Incremental improvement.
