Visa’s release a new iPhone app last month. One Bank has signed up (US Bank) the rest are holding back (more on this below). The application has been a 2 year effort driven by Monitise, and the UI looks very good. However, I’m afraid that Visa’s latest mobile effort is doomed to failure because of the "last mile" issue at the POS.
Looks like I was a little premature in the original version of this post. Looks like the pilot may be a field trial for NFC as in the Micro SD form factor.
PayPal is best positioned of any major player to link the virtual and physical payment worlds (see here for detail): they have a consumer base, merchant base and a phenomenal fraud/risk team of 300+ with commensurate tech and ops. However their ability to execute is not without challenges. For example, what % of their current merchant base does POS transactions? Will there be a need for merchant terminals? If so who will pay?