Given the fact that some upper-range e-bikes can travel pretty fast, it's definitely important that they don't skid uncontrollably when braking. ABS solves that problem.

A new model from Stromer is the first with fully frame-integrated ABS. The ABS in Stromer's ST5 incorporates an electronics module inside the bike's top tube, an actuator connected to the front hydraulic disc brake, a wheel speed sensor on the front wheel, and a top-tube-integrated display which confirms that everything is functioning properly.
If the system detects that the front wheel is ceasing to turn while the bike is still traveling forward, it intervenes by continuously modulating the hydraulic pressure on the front brake, keeping it from locking the wheel up. The system is likewise able to detect if the rear wheel starts lifting under heavy braking, and responds by adjusting the front braking force accordingly.
The Stromer ST5 ABS should be available next summer, with prices starting at US$10,000 / £7,400. The good news, of course, is that an innovation such as ABS will eventually come down substantially in price and is likely, therefore, to be fitted to more run of the mill and affordable e-bikes in the not too distant future.