Not sure on how long the Bitcoin life is because much can happen but I think that Bitcoin is going to be around for a while because it is the future.
Bitcoin already is popular and I am sure that it will become even more popular later on.
As I know, Satoshi speculates that bitcoin will be the currency of the world on 2050. People use to switch from USD, EUR to BTC in that time. I wish same like that. I hope bitcoin will be mode of payment for banking in some years. We ll hope for the best.