It doesn't steer. It augments the cruise control, accelerating and decelerating in stop-and-go traffic (see https://www.youtube.com/watch?v=PcwObeGB_mU). Which isn't nothing, but it's not driving you to work.
I've heard them claiming that it could indeed drive you from home to work using public roads and that it is capable of finding you and driving the car to you when you call for it (aka. "Batmobile mode").
Hm, I didn't know that. (Edit: it doesn't seem to be out yet?) And some cars can steer around corners on the highway. But it's very limited, doesn't necessarily work in the dark or in bad weather - and most relevantly it doesn't actually navigate by itself. It just follows marked roads. To use the self-driving lawnmower, you have to mark out an area for it to mow.