Michelle thought it would be a good idea to have an app policy that the developers agree to when submitting their application.
"We reserve the right to disable your application, remove or restrict you or your application's access to OAuth, and pursue any other course of action we deem appropriate if we believe, in our sole judgment, that you or your application are violating any policy, guideline, and guiding principle of the Wikimedia Foundation.
We can change this Application Policy at any time without prior notice, at our sole discretion and as we deem necessary. Your continued use of OAuth constitutes acceptance of those changes."
She is willing to work with us to come up with a more official policy.