I think Wikipedia could further open up to external interaction if it provided simple means to interact with the data. For instance, serving pages as XML or even plain text could be one of these ways. That way, third parties could allow users to check out Wikipedia content easily. Also, updating the data via simple methods, such as XML strings sent via POST following the same DTD would allow third parties to also integrate this feature.
You may argue that simple data posting would tempt vandals--a determined vandal can just as easily hack the system as it stands right now, writing a script to send zillions of regular HTTP POST requests isn't such a big feat. Formalizing the data in a DTD on the other hand could tempt serious third parties to join the game.
Is there anything like this already implemented and I haven't been able to stumble across the documentation?
Gutza