I think, because of synergistic network effects, we will see one chain become dominant over time. I could be wrong and this depends largely on scalability. Spillover effects from lack of scalablility could cause this dominating chain to lose market share to competing chains.
The code can be replicated, but it should prove difficult to fork the code and compete against the incumbent. IMO, bitcoin has been obsolete for years, and it HAS consistently lost market share, but it is taking time for superior chains to overcome bitcoin... and there is a chance that it may never happen. I think in the next 5 years we will see a superior chain overtake bitcoin on all metrics.