I don't think that it will ever disappear, because there's a lot of money to be made, even if you counter out all the advantages it has as a currency,
and a point of value media.
Another point is that it's also the very first crypto currency, and that it's decentralized - so it can't be controlled or simply shut down.
Just because most people don't use bitcoin now doesn't mean they won't use bitcoin later. Sure, I believe that bitcoin won't really ever grow out of the stereotype that only people who use the Internet often use bitcoin, but I'm positive that bitcoin will expand to many, many more people. Merchants are sometimes pressured by clients to accept bitcoin, and sometimes the merchants themselves begin to accept bitcoin because of the fact that there is a wide audience of bitcoin-ers. Plus, there are plenty of people who think that the concept and details of bitcoin are highly interesting and then get into bitcoin like that (such as me).