jaws 5.0 adds new implementation:

With the pending release of jaws 5.0 which is now undergoing testing by the
public with no restrictions as in the past, there are numerous features that
bear on our implementation senarios.  One is natural language rendering.
Jaws with eloquence can now speak the language of a site which has been
marked up with the lang attrib automatically.

Another is the introduction of sound schemes and voice aliases which further
enhance the ability of users to be provided with ui and site information in
different voices and sounds.

yet another feature is the ability of jaws to tell you now when there is a
mouse over on an element and often that mouse over can be activated.

There are many more features in the new jaws 5.0 and you can read about them
and shortly be able to download it at:
 http://www.freedomscientific.com/fs_products/software_jaws5pbintro.asp