Bitcoin has the critical mass going for it, with many merchants accepting bitcoin for example as well as other companies creating easier methods of buying and selling.
This critical mass is important. For most on the cutting edge of development, they can only really concentrate effectively on one coin so as not to dilute their efforts. For the near future at least, it appears that Bitcoin is it.
I would tend to go along with this. Bitcoin is way out in front, so far in front of the rest that it would be hard to imagine any of the rest catching it now. However, I am also acutely aware that practically none of the big internet based companies that were around during the tech bubble, are market leaders these days or even still around. Without knowing a great deal about the technology I don't suppose it would be beyond the realms of possibility that there turns out to be some design flaw in Bitcoin that eventually renders it untenable over the long term. Perhaps the computational power required to keep the Bitcoin universe functioning will become to great or perhaps someone will crack the algorithm and start forging coins. Who knows, but history tells us that
New Invention mk1, never lasts the duration and improvements are always required for a concept or technology to succeed.
Who knows, perhaps one of the pump n dump coins will be in a good position to take Bitcoin's place should anything bring it down for whatever reason, or more likely is, that the Google or Facebook of crypto-currency is not yet with us.
Bitcoin is more like a protocol. TCP/IP has a lot of issues but the network effect has kept it around despite theoretically superior alternatives. If TCP/IP didn't exist today and you were building a new protocol from scratch you wouldn't make it as crappy as TCP/IP is however the network effect has killed off the potential of an alternative. Does Bitcoin have a large enough network effect to hold back competitors? It remains to be seen but IMHO a competitor would have to be VASTLY superior not some improvements around the edge to displace it otherwise Bitcoin issues and all will be like TCP/IP. People will build around it to improve the rough edges. To stretch the metaphor somewhat TCP is stateless, oh noes that means you can't handle state on the internet right? No. It just means people designed higher level protocols to record user state at both ends while the underlying protocol (TCP/IP) remains stateless.
Now someone reading this is likely thinking what about TCP/IP v6 (64 bit addressing). Well that is a good point. This is more an evolutionary change not a radical new protocol and the rollout of this evolutionary improvement has been glacially slow (timelines measured on a decade scale). Why? Is it because TCP/IP v6 will suck? No. It is just that the current protocol is "good enough".
Who knows, perhaps one of the pump n dump coins will be in a good position to take Bitcoin's place should anything bring it down for whatever reason,
Or not. They are 99% carbon copies. Anything that kills Bitcoin will likely kill them too. For example the most likely cryptogrpahic break will be in ECDSA. Hashing algorithms are generally pretty resistant to cryptoanlysis. Hell Bitcoin could have used SHA-1 and despite some theoretical breaks, everything would still work fine today. Public Key cryptography however is far more vulnerable both to Quantum Computing AND to good ole cryptoanalysis. If ECDSA is broken tomorrow (or the particular curve used by Bitcoin is found to be flawed) that break would affect every single clone coin. Every single one uses ECDSA. Hell not only do they all use ECDSA they all use the EXACT SAME CURVE.