A few features that this should have....
The ability to switch into a fullscreen theatre view
much like J River´s Media Center or even better yet,
Meedio Essentials. If you can clone Meedio Essentials
interface, it would be flawless. It should also include
a PVR built into it. Don´t forget to include resume
play feature so if the computer goes into standby, on
resume the media can pick up where it left off. Also,
it should be able to have full control over alsa and/or
ogg, such as shutting them down or restarting them.
And of course this implies that it can monitor alsa/ogg
continously for maximum performance. Good luck guys!!!