To be honest, I would rather see the rails converted back into...rails. There is a desperate need for an efficient mass transit infrastructure in this country, which a revived railway would create (or re-create, as the case may be.) Multi-modal commutes are probably the wave of the future, with the bicycle only one mode of several. And there really is no need for an additional infrastructure for bicycles, the roads are already there. Modification of the roadways might be helpful (not as in more bicycle lanes, but as in traffic calming measures to slow motorists).

Rails-to-trails? Not so useful. Too slow, too dangerous.