No, I haven't had time to install any extras-testing, or extras-devel, or compile any software myself. Studying for Final exams right now. I just remember seeing screenshots of Mediabox in development for Fremantle (Maemo 5) and posts (you can find a thread in the Multimedia forum) if you'd like to follow development.

Pycage, the author of the software, is quite active and responds to the thread often.