To see where this might lead, consider the UK, where this is already the case. The Equality Act 2012 [1] (which itself is a replacement for the Disabilities Discrimination Act which also applied to websites) requires:
A person (a “service-provider”) concerned with the provision of a service to the public or a section of the public (for payment or not) must not discriminate against a person requiring the service by not providing the person with the service.
It applies to websites (Airline BMI Baby was sued by the National Institute for the Blind for failure to meet the as-then Disabilities Discrimination Act).
The typical paraphrasing I hear from developers is that it requires an organisation (but not necessarily the developer) to make "every reasonable effort to comply", for which there is a baseline of appropriate colour contrast and reviewing WCAG validation.
It does mean that developers for UK-based services are less disposed to Javascript-heavy applications/components and video content (because of the requirement for ARIA and transcripts/CC respectively).
The typical paraphrasing I hear from developers is that it requires an organisation (but not necessarily the developer) to make "every reasonable effort to comply", for which there is a baseline of appropriate colour contrast and reviewing WCAG validation.
It does mean that developers for UK-based services are less disposed to Javascript-heavy applications/components and video content (because of the requirement for ARIA and transcripts/CC respectively).
[1] http://www.legislation.gov.uk/ukpga/2010/15/part/3/crosshead...