Please excuse us for the delay.
We started implementing the WAI ARIA support for the previous service pack release, but again the tests with JAWS screen reader were not satisfactory enough.
It seems that the screen readers still have some issues with WAI ARIA.
That is why at the moment we can offer a partial WAI ARIA support.
However we started researching these issues in order to find a way to overcome them.
At the upcoming Service Pack we will release an initial version of WAI ARIA support feature - you can download this version and give it a try.
Please note that this feature is yet to be improved and enhanced.
All the best,
the Telerik team