Very likely, when all transactions can be done by yourself without any bank will certainly make the banks deserted and slowly can close the business. I'm sure if everyone using bitcoin, then the bank will close automatically but no time soon, because the user has not been much bitcoin.
Bank is already an institution and it is just simply hard to erase it in the face of the world because of bitcoin. They can work together though but not necessarily remove one over the other. Majority transactions are still involving bank transactions and it will stay here for awhile or maybe until the end of the world.