NFC has been a bit of a non-starter for Google, they launched the technology baked into the Nexus S as the end of 2010 and it didn't really have a use until they launched Google Wallet on Sprint near six-months later. Of course, Google Wallet became one of the first contactless payment systems to make much sense, it was easy and seemed secure.
Since then, Wallet has been quietly trucking along - save the odd security snafu here and there - with very little fanfare until the Galaxy Nexus launched on Verizon. It was then revealed that Verizon would be shipping their variant of the phone with their own wallet system, a pretty big blow to Google Wallet, not having the US' biggest carrier go in with your payment infrastructure must have hurt. The workarounds for this were well documented at the time and it wasn't all that hard to circumvent at all.
Things seemed to have changed for the fledging wallet system when Sprint used Google Wallet on their Galaxy Nexus - even giving customer $50 credit to spend - but, it's now said that the one carrier willing to let Google Wallet have it's day in the sun is changing its mind. Last summer, AT&T, T-Mobile and Big Red invested $100-million each into the Isis NFC wallet system. It's strange to see that perhaps the one thing that would unite the carriers is a desire to distance themselves from Google.
Sprint are now said to be developing their own contactless payment system, rumored to be called Touch. If the service is to come to light then this may well be another nail in Wallet's coffin. As NFC technology launches all over the globe with no standard emerging yet, it's going to be interesting to see how the carriers in the states play the game and whether or not big business will back them all the way.