missed a few
A PC with adequate storage could also make a very good music or movie server with little consideration to format or DRM. With HD on screen control to boot.
If the software was ever created room correction could be built in.
1 PC could replace a pre-amp, PEQ, optical disk readers, OTA, cable & dish STB(s), DVR(s), media servers, game systems, video scaler. I can't think of anything that could not be squished into a HTPC* but the power amp, display and speakers.
* With proper hardware/software support. As it is now some aspects are tough or impossible to excecute.