"Soon" would be in the next 1-3 years or so.
One of the biggest dangers for BTC is something more useful coming along and investors switching - a process which could happen extremely fast, once started.
So to all the tech savy people in here - what advantages could other cryptocurrencies bring that will give them a crucial edge over BTC, and how fast could something like that come along?
something good do you mean is altcoin? I don't see that potential in any altcoin, if you have found it I hope you will let me know later.