Banks will change or go under but they won't go away. They will always find some service to provide that someone else will want to buy.
I think so too, banks will never disappear. Even though bitcoin is popular and most country use it, it cannot make bank disappear. Im sure bank will go with the flow or catch up with the trend. They will improved their system or think something new to catch up with the evolving currency. Maybe they can think in the future on how they can cope up in the popularity of crytocurrency. Or they will invent something that can use so that they can use cyptocurrency or its concept on their advantage.