Semi-recently I switched to Rdio from Spotify and in doing so I was forced to revisit my iChat-Spotify-AppleScript post. I have adapted the script to work with Rdio and have also made a few updates. For one, iChat is now Messages and, of course, Spotify is now Rdio. I also made some changes that makes the script check if Rdio is ready before attempting to retrieve the track info.
Rdio has basic AppleScript support, but I am hoping that Rdio adds short URL support for AppleScript, but for now we'll have to survive with the long version.
You can find the AppleScript I wrote on GitHub.
To run the script I am using the workflow feature of the latest version of Alfred. When I invoke Alfred, I type the keyword "status" and it launches my script.