It varies from state to state. Kansas is finally jumping on the bandwagon. However, I don't know what the program consists of. I think it's around 12 - 18 months provided all other pre-reqs are met. There are 2, maybe 3, local community colleges offering the bridge starting Fall 05.
If you ever wonder what paramedic continuing training/patient contact consists of, I urge you to go spend a 'day (or week) in the life of' a medic. They would be thrilled to have you! (not kidding, either) I'll bet they do/know more than you realize.