http://thefraserdomain.typepad.com/energy/2007/04/usa_today_had_a.html

Wave power is steadier than wind, river power is even better.

As hydroelectric dams come down and river current power comes on strong, what percentage of electric power will come from water power?

I think it will be 25%.  Another 25% from large wind power installations offshore and in high wind areas like the great plains.  The rest form conservation ( geothermal heating/cooling, direct solar heating/cooling, super efficient appliances, tvs, computers, ultra-efficient vehicles, mass transit and telecommunting for work, robotic organic agriculture)  and distributed renewable generation from rooftop solar, biomass to biogas, and small to medium local wind power.