One major obstacle toward Bitcoin's acceptance by the mainstream is its extreme volatility. Effectively, this volatility means that Bitcoin is more a commodity than a currency.
That being the case, if, and that's a big 'IF', we wish to further the cause of Bitcoin as a currency with mainstream acceptance, there needs must be a mechanism in place to 'dampen' the volatility.
Central Banks stabilise their International fiat currencies through some exchange rate mechanism, that prevents excessive volatility. Can a similar mechanism operate for Bitcoin?
But, who will be in charge of a setup that is not just intentionally decentralised, it is explicitly anti-centralised?!
Are these just the design limitations of Bitcoin that we have to put up with; or can Bitcoin evolve?
Things that tend to dampen volatility are widespread adoption and use, lots of volume on exchanges so price doesn't move very quickly, and intrinsic value.
Bitcoin has some serious challenges for widespread adoption, and its decentralized, leaderless nature pretty much guarantees those challenges will not be effectively addressed for the time being.
A centralized exchange rate mechanism would pretty much defeat the purpose of decentralized peer to peer transactions, so I wouldn't recommend it, and I don't think it would work anyway.
I don't see Bitcoin evolving in a way that could curb the volatility, though it might be dampened somewhat by significantly more speculators getting into the game.
For an example of a cryptocurrency that is proactively addressing these challenges with Bitcoin and gearing up for widespread global adoption, take a look at DNotes and its sister company DNotes Global. The project is not widely known at this point, has been operating largely under the radar, but over the past four years it has been very steadily and quietly building up and putting together the pieces, and one day, probably in the next couple years, it's going to take the world by storm. All of a sudden, there will be a digital currency that seamlessly bridges the gap between cryptocurrency and traditional financial structures, that is totally user-friendly and intuitive to use, and which is supported by an extensive ecosytem to give it intrinsic value. You don't build something like that overnight, but for most people it will appear like the proverbial overnight success.