Just like we have laws against discrimination based on disability and measures like handicap parking spots, does anyone envision a future where there's some sort of federal mandate that websites cater to the disabled?
At least in the US, this already falls under Section 508 guidelines [1]. Most government web sites are already expected to follow this.
I wouldn't call it "catering" though, because often it doesn't involve anything more than semantic markup and avoiding exclusively mouse-driven navigation.
It's already a de facto requirement for anyone selling software to the government. When I was a PM at Microsoft working on Visio, I was surprised and amazed at how much time and energy went into accessibility of all the Office product. It's not easy to make a visual design program like Visio work well for the blind or visually impaired!
I'm trying to think how a blind user could effectively use a visual design program or its output. Do you output text representation of diagrams? Does a blind user put the product to some use and purpose that's different from the average sighted user?
If the visual representation can be described with data, you give them the option to view that data. Images have a longdesc attribute for this http://webaim.org/techniques/images/longdesc
Not all visual applications can be made accessible.
Changes to the law seem unlikely given the dysfunction in Congress now and in the foreseeable future. Hence, we may end up with a regulatory patchwork quilt made up of rulings like this one.
