Patently Apple reports that this week's issue of the USPTO Official Gazette included patent 8,459,544 -- "Parental Controls." Though the patent certainly shows a growing interest in mobile payment, the narrow claims and limited applicability don't give too much insight into any upcoming revelations about Apple's product line.
The patent describes a system to controlling epayment spending from a "subsidiary" user of an ewallet account. For example a parent controlling the amount of money a child has to spend on iTunes.
More importantly, I think this particular patent likely demonstrates a "fleshing out" of smartphone-based mobile payment systems, which Apple seems to think (and the rest of us probably should think) will become pretty important.
From '544: "As we move to a more mobile and fast-paced society, the use of cash or currency is being increasingly replaced by the convenience afforded by payment cards, such as credit, debit, and stored-value cards.”