Since there's a lot of new people to Tesla and the forums, I thought it would be worth explaining what was announced at the reveal last night in regards to autopilot on the 3.
He said that the autopilot hardware and the autopilot safety features come standard. That means that the camera(s)/sensors/radar(s) will be in every Model 3, and that the safety features that help the car avoid accidents (auto braking, side collision avoidance) will be active on all cars as well.
However, full autopilot is a software feature that will be an extra option. This is how it is on the Model S and X as well. Every car is made with the hardware, but if you want the software you pay the $2,500 option when you buy the car, or $3,000 upgrade later. It could be different pricing on the 3, but we'll just have to wait and see.