You can watch our Google IO 2011 on Levarging Android Access APIs. The main take-aways from the talk:
- Android Access is easy --- the framework does most of the heavy-lifting.
- Implementing Android Access does not mean you take a performance hit.
- Accessibility is really about expanding the reach of your application.
Implementing accessibility within your application and thereby ensuring that it is usable in a wide variety of end-user scenarios will benefit your application --- both in terms of the number of users you gain, as well as how often your users use your application.