diy surround system?

[yander]

I was recently looking at purchasing a new stereo system, looking around I see that some of the new systems, offer things such as hardware and firmware upgradeability. It got me thinking, would it be possible to build a surround type stereo system based on a computer with a high quality sound card? I know a lot of sound cards have 7.1 channel sound outputs, some have digital inputs also. All you need is a card that is capable of switching the inputs, some amps of your choice and you have most of what you need. It would seem that a very simple computer with a scaled down OS like Linux tailored for such a task and a small lcd screen mounted in the case could be made about as capable as today's surround systems. I know people make there own HTPC's that do have high quality sound cards, but I am suggesting something that would act and look like a stereo system. Even some of the more advanced functions found in high end surround systems could be incorporated such as video up scaling as funds and needs apply. So far I haven't found any diy projects like this, I am just looking for opinions and possible road blocks.