Whewnever the mainstream pushes it into the next bubble, perhaps even the bubble that breaks the system.  Think about it, it isn't a bubble yet, but after significant rises once it gets hyped by the mainstream and all the highly leveraged players enter the market, the profits from Bitcoins and alt-coins will get ridiculous, and as soon as their price drops the fiat system will crumble.  People always argue about whether Bitcoin is a bubble, and I say not yet.  But eventually I don't see how there won't be highly leveraged players attracted to the profits and then it would get pushed into a bubble.  We are far from that scenario, but I'm waiting for that to happen before I cash out.