I thought that I was the only one who has even considered this. MPXPLAY is the only program I've used since getting into this. It has all the features I want for dedicated mp3 playing, including crossfading. Even though my current setup is smaller and lighter than a normal desktop, I'm always looking to going smaller.
I'm currently researching the use with a mini-itx epia board. Overkill for DOS and Mpxplay, but with prices getting lower this could be a very small, very fast mp3 player that has the ability to be a full blown computer when needed.