Until banks get developer friendly and support OAuth, I'm not sure what else you could do if you want real time verification. I guess micro deposits could still work if you had faster rails, but ACH is still a batch process.
We may wait a long time for that one.
Also, there's been a lot of work done through the Fed's remittance coalition on a supradirectory for destinations. Adding authentication capabilities would be the next logical step and they've already committed to using open standards (lots of ISO stuff to compete with though). Combined with whisperings of big bank projects and JP Morgan's CEO very vocal hatred for screen scraping, Oauth could be a powerful and quick-to-market alternative.