The only reason this "problem" remains to be solved is that the US banking industry can't get their act together. Most of the rest of the industrialized world has had near-instantaneous bank-to-bank transfers for more than a decade. Here's a good story contrasting the UK system with the US: http://www.npr.org/blogs/money/2013/10/04/229224964/episode-...

Expect all of these virtual wallet payment systems to die a swift death once Visa/Mastercard/Citi/Bank Of America/Chase finally pulls their finger out.