It does not work with anything yet...
1. Apple have not yet released iOS 4.2 which is needed in iOS devices for AirPlay to work.
2. Manufacturers have not yet released any speakers that have AirPlay built in yet.
Well, I certainly hope that this could be accomplished through a new piece of hardware/software in connection with my existing zeppelin. I'm not sure I want to spend another $700 just so I can stream music to it, although this does sound like a whole bag full of awesomeness.