The real question is: how much value can a cryptocurrency have when anyone can create one?
This question is important, not because it spells the end of cryptocurrency, but because it might be the beginning. What if, for example, the US Federal Reserve and Treasury Department announced tomorrow that they were minting their own form of cryptocurrency and that it would enjoy the full faith and credit of the US Federal Government? Would Bitcoin's value in USD would fall through the floor, or would it gave speculators confidence in this newfound technology. In this way, cryptocurrency is just a new kind of paper to print money on. Eventually governments will get involved, and how they get involved will be very interesting to watch. I doubt that we'll see any one nation successfully introduce their own cryptocurrency, but I could see one with a very shaky economy decide to pin their physical currency to a cryptocurrency. There are already some people pointing out that, in these weak economies, the transactional value of BTC is massive to those parts of the world. We are already hearing talk about banks implementing their own form of blockchain technology. The technology is real and proven, but will the ever-growing list of crypto's be able to capitalize, or will they fall to the wayside as institutions take advantage of the technology utilizing fiat currency.
On the side of the lesser currencies, I think that the momentum of Bitcoin will continue to propel it forward, but alternatives like Litecoin and Etherum will continue to have as much value as they introduce through innovation. Newer currencies will have a harder time getting established, but that doesn't mean they're valueless. The smaller the marketcap, the less risk, and the greater incentive for technological advances. Essentially, we're in the land-grab stage of cryptocurrency development, and the real estate that these other currencies have carved out for themselves will only become more significant over time.