I think it's highly likely that there are two main scenarios for
Bitcoin's economy in the next decades:
1) a
speculative & volatile scenario with possible high ROI but also high risk:
Bitcoin continues to be used mostly like today. People (and also businesses) buy it because it's volatile and can yield high ROI if you catch the correct moment to enter and sell near the peaks. In this scenario, we will continue to see wild price swings, spectacular bull markets and insane crashes after massive profit takings. But that would limit adoption to people (and business) with money they can afford to lose.
Price growth would be higher than 30% in most years, sometimes 50% or more, but there is also the possibility of deeply negative years with 50% loss or more.
2) a
boring / stable scenario with higher adoption by common people.
Volatility will decrease further driven by more and stronger hands involved, possibly also by BTC adoption "as a currency". You won't get rich if you invest in Bitcoin, but you can store your wealth safely investing in it. So the adoption by "retailers" would be higher, as people with normal salaries can use Bitcoin for their savings without having to fear a deep crash.
Price growth would be less than 10-15% per year, but even in bear markets never more than -10%.
More details about the scenarios
in this post in another thread.
I would like to know from the Bitcointalk community which scenario you prefer. I think still both scenarios are possible at this stage and have a similar probability.
On purpose,
I haven't included a "moderate" scenario. It is far more interesting if people would prefer high but risky ROI or a slow, stable growth, otherwise people would gravitate probably to the moderate scenario.