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.
I think this is difficult because there are people in the world who think bitcoin is too risky and that they will put their money at the bank's steady investment rather than the more adventurous bitcoin. Conservative and radical right or wrong, but different directions.