The Ma.gnolia team have just announced the Ma.gnolia Developers Center, and their initial foray into OAuth support! This is a great step for anyone who is interested in building apps based on Ma.gnolia, as well as anyone who wants new and exciting ways to access and use their bookmarks.
When time allows, I will implement some changes to the Ma.gnolia Plugin for WordPress, and will definitely dig into the available APIs to see what I can do and how I should do it. If I can figure out OAuth quickly enough, it may even give me the capabilities to expand the reach and purpose of the plugin, which would be no less than stellar.