Bitcon will die and we will see absolutely new cryptocurrency
That is probably going to happen, I like to compare btc with netscape. We just have to wait for Mozilla, Opera and Chrome to be released, now.
This can't be compared and won't likely happen.
All these coins that market themselves as second gen. are useless scam attempts. Nobody is going to make a coin where he/she won't profit to the maximum. Nobody is going to try making a coin that will benefit the people.
As for OP, you can't really know what is going to happen.
The money that we use today might not be used, it might be all cryptocurrency, then again it might not.