Hi,
I am already using rapsberry pi for media purpose. Could you provide more detail about this project? We can have videos and create playlist that will be repeated one after another and we can configure this list or currently playing item remotely using web browser on the same network where raspberry pi is connected. Controlling via internet is transparent to raspberry pi, but it should be connected to internet in that case. Note, raspberry pi is having very limited RAM (512 MB shared) and so we need to keep CPU intensive tasks offline like huge file copy, playing unsupported video file using software decoder etc.
Thanks!