Some developer background..
In Moodle 2.3, I converted the Google repository/portfolio plugins to authenticate using OAuth 2.0 as this was the recommended way forward from Google. Much of this work was simplified as I had already created a skydrive plugin for 2.2 using OAuth 2.0 (there were no good php OAuth 2.0 libraries at the time). Both Google and Microsoft now authenticate for their apis using OAuth 2.0 and so in lib/oauthlib.php we now have an OAuth 2.0 client class which is used for both Microsoft and Google. This plugin was updated to work with the new class in Moodle 2.3. Hopefully all the rest of the repository plugin providers will convert to OAuth 2.0 soon. Hurray for open standards :)
Thanks to Universidad Teconológica de Chile (INACAP) who funded this plugin to be created by LUNS and to LUNS for releasing this work open source, allowing me to continue to work on this for Moodle 2.3.