I think banks will not disappear.
They can change or can work with bitcoins.
but they will never disappear as fiat will never disappear too.
If fiat comes to the point that has no use already,
then thats the only time that banks can disappear.
But as i have said, its impossible.
I also think that bank will not disappear but there is a chance the people will choose bitcoin rather than bank. Why? Because in bitcoin there is no tax and you are the one who can manage your money on a wallet. Here in my country there is wallet where you can manage and make most out of bitcoin. You can buyload , paybills or even convert with ease. Not like in banking you need to go to bank everytime you will do transaction . Maybe in the near future bitcoin will be populat and more people will choose bitcoin rather than banking.
Banks will never disappear but after knowing bitcoins people will start using bitcoins more and will reduce usage of banks but they will not totally stop using banks as they also need for their day to day transactions so I don't think that banks will completely disappear in future.