Most practitioners know this, but it is important to consider that the real benefit will come as behaviour change towards a new way of saving and lending/borrowing. With better information access for savings (how much have I saved; at this rate, when will I have enough; etc.) and lending (what is the outstanding balance; when will I repay my loan if I increase repayment; etc.), "mobile money" will lead to more educated consumers. But it is also the process that will get streamlined, making it more cost-effective and applicable.
However, the most exciting potential is to re-invent savings and loan products to be more relevant to the target market. By packaging products in a different way, think of re-payments differently and interest rates/penalties/admin fees structured differently, this is where we will really see "mobile money" have a lasting effect.