The June issue of Motorcycle Consumer News contains a news item regarding the new EU ABS requirement legislation. As of January 1, 2016 it will be mandatory to fit an antilock braking system to all motorcycles with an engine displacement greater than 125cc. (There is no mention in the article that this regulation will apply to electric motorcycles, but you can bet that they will fall into that category.) Smaller motorcycles with displacements between 50cc or more will be required to have either ABS or a combined brake system, mechanically linking the front and rear brakes.
Also, the way I interpret the article, it sounds to me like home-built motorcycles licensed for the road after 2017 would be required to be equipped with ABS systems.
According to a study funded by Bosch (a major supplier of ABS components), "standard-fit ABS can prevent more than one-quarter of all motorcycle accidents with personal injuries". Since 2010 Bosch has been manufacturing the worlds lightest ABS system designed for use on motorcycles.
This "Generation 9" ABS system is offered in several variations for use on production motorcycles. ABS 9 Light, due to be launched this year, is the entry-level version. It ensures the antilock braking control of the front wheel, making it suited to low-cost motorcycles which have only one hydraulic brake channel (such as bikes with a mechanically operated rear drum brake). The Bosch program also includes the ABS 9 Base, which offers ABS functionality on both wheels, the ABS 9 Plus and the ABS 9 Enhanced, with additional eCBS (electronic combined brake system - I think) function. This system automatically activates the second brake, without any need to operate the brake lever.
Bosch also is introducing a combined ABS and traction control system that will function even when cornering. This MSC system requires the new Bosch SU-MM5.10 lean-angle sensor to be installed on the motorcycle.
I think we can expect all Brammo models to be supplied with ABS systems by the 2016 model year.