In future, when bitcoin will dominate in sending - receiving - depositing funds kind of bank works, I believe banks will start different type of banking like providing safe vault or mortgage kind of services alone. Banks will fall.
I don't think the banks will fall either just because of bitcoin. Remember who is with banks and that is the supreme government of a country. And I don't think that government is going to allow it for banks are really important in a cycle of an economy of a country but I think that bitcoin will be considered by government too.
Another possibility is that banks and governments will begin to create their own crypto currencies market them as the next big thing and claiming that is better than bitcoin, people being people will fall surely in the trap and that way banks will be able to make money out of crypto currencies.
Although, it would be a great and major breakthrough for everyone in the cryptoworld, but I don't see it happening at all and if it will then not anytime soon because the population to effect that is the first considering the number of people involved in the banking system, the regulation compliance there too, couple with the infrastructures in place in that sector, I dont see Bitcoin just bypassing all that and make banks disappear without a fight at least in the longterm.