This joint venture is part of their plan to topple the standard credit/debit card industry, which would be redundant if consumers switched to mobile payments. The payment system works using NFC, or Near-Field Computing, which would allow a merchant's point of sale to communicate with your mobile device.
Mobile devices are encroaching upon a number of other fields, like GPS navigation, portable gaming, and now financial services. It might sound odd for your carrier to handle your third-party billing, but it stands to be a perfect combination. As they handle millions of accounts, and billions of individual charges every month, wireless carriers are prepared to take on a larger role in your finances.
The project will face stiff competition from other emerging services, like those of Visa, Sprint, and Apple. Retailers like Starbucks have also created their own "mobile payment" option, but it requires more effort and forethought than would an integrated e-wallet solution. Despite the success of e-wallets in Turkey, Japan, and the U.K., many consumers are wary of security concerns. But aren't our credit card numbers getting stolen all the time anyway? Many of us look forward to not carrying a wallet.