... I know the Myspace analogy technically isn't that great of one. I'm speaking more in terms of Bitcoin being over-hyped and there potentially being a better successor to come along.
You have to understand the context of "better successor". Bitcoin was not an incremental improvement on prior attempts at digital cash. It was a large breakthrough in computer science (specifically solving global consensus; the "byzantine generals problem"). The problem stood unsolved for decades. The network-effect surrounding the solution to this problem as applied to digital money, as you can see with bitcoin's success, is huge.
Possible incremental improvements over the current implementation details of bitcoin are nowhere near interesting enough to unseat bitcoin's dominance. It's not proper to compare bitcoin to specific companies (FB, Myspace); a far better analogy is core internet protocols.
Bitcoin is the first viable protocol for trustless exchange of value. It's more analogous to things like SMTP or IP. Did improvements to those protocols exist? Of course... But when we're talking about things that are a large break from the past, "good enough" plus first usually wins over incompatible alternative approaches.
It's also worth noting that these protocols evolve and incorporate new ideas. Bitcoin has the same properties; if new ideas come along that are indeed very beneficial, it's likely they'll be incorporated into bitcoin.
For me to get worried about successors, I'd have to see fundamental new solutions to the problem of achieving trustless global consensus over an insecure network. No alt does that. And even if one did come along, I'm not sure quite how it would do it massively better. The fact is, bitcoin's consensus solution works, and that's all it takes to launch the virus of digital money.
