gnopernicus reads a "switch to window" message when a new window gets the
focus. I've filed a bug about it, because it doesn't tell you what the
window is. you can see it here:

  http://bugzilla.gnome.org/show_bug.cgi?id=111853

so, this will be cool once it is implemented, but there's one thing
missing: metacity doesn't tell you which window it's *going* to switch to
when you're in the middle of alt-tabbing (because it doesn't actually
change the focus). 

somehow, metacity needs to tell you the name of the window as you alt-tab
around. i'm not sure how that will be achieved, but it will enhance our
a11y support. :-)

thanks!