Time Capsule as media server?
My best advice would be to invest in a NAS. Their software is much better for doing what you need. Synology is my favorite as their software is very intuitive and Mac like. A NAS also lets you do more with it like backup files, use it as a web server, host a blog, download files directly to it and stream both music and videos. If you check out our forum, @ mkvxstream.blogspot.com we have links posted to live demos of both Qnap and Synology. I know it's another piece of hardware but a NAS is much more versatile than Time Capsule.