You do know that by having you CC info in the Play Store, it's already in your Google Wallet right?
Where I can use NFC, the experience is nice. Granted I haven't really used any of the other stuff in Google Wallet (coupons, loyalty cards, etc), but the ability to pay by tapping is very cool, and always gets the attention of those behind the counter (usually "What phone is that?" or "How can I get my phone to do that?").
I think the card is meant to be used in places where NFC isn't available.