Bike sharing systems in cities around the world have experienced different degress of success. The new system planned for NYC is doing the right thing and getting a lot of community feedback on station locations - here is the current proposed map.
I'm struck by how quickly bikes are turning up in certain areas of Manhattan and Brooklyn. Infrastructueand laws still need to be improved - of immediate concern is pedestrian safety. The city is a long way from the world leaders, but bikes and NYC seem like a natural fit. My guess is the new sharing system will be a big hit with 20 somethings and college students.