There seems to me considerable hope that in just a few years the banking sector will be completely redundant. I'll make this prediction now and lets see if I'm right...
Banks are of use to the average customer only for three reasons.
1) Somewhere to keep your money safe.
2) To facilitate transactions.
3) Credit
Now with peer to peer sites emerging like www.zopa.com savers themselves can actually earn the interest made on loans made with their money rather than the banks. We will be able to find loans directly from individuals and groups of individuals, no need to ask a bank.
If bitcoin or something like it were to gain widespread acceptance, we'd have a peer to peer electronic currency. We could encrypt our money, and send payments with our mobile phones.
With users taking the proper precautions it would be a safe store of value. No need for banks.