To be honest, it wouldn't be too hard. In fact, if you made an external (eg. Windows) program to set the username and password, you'd be able to integrate with Yougle right now.
I'm looking at adding a username and password option to the program for other sources, but as yet I haven't found sources that really NEED it. Although people are starting to ask for access to the over-18 features of DivX Stage 6, so perhaps it'll be out soon.
In the mean time, if you want to work on a source I can help you with it - hard-code your username and password for the testing phase, and by then I may have a username and password system set up.
Author of 'EMUCenter' to play arcade classics 'MoreWithMyMusic' to sing with and normalize your Music, 'Yougle Vista' to watch YouTube, DivX & More and 'BlindTimer' to time your poker game.