Bitcoin can not make banks disappear because it has not parallel system to replace all the things what banks are doing and services they are providing. Bitcoin has controlled a large portion of banking services mostly online related things already and that is sufficient to keep focus on. They will exist in working together atmosphere continuously.
i think bitcoin can replace banks as we can see that the new trend of the new generation is toward online trading and shopping, they mostly do shopping online, and the the trend is now even in progress in underdeveloped countries, so if all the people of the world start using crypto currencies then there will be no use of banks and banks will automatically disappear,