Check out these links for some info
http://groups.yahoo.com/group/hpde100c/

http://k0lee.com/de100c/

It is basically a standard pc running linux with a custom player application.

Here is all the ports:
S-video
Composite
VGA
Digital audio optical and coax
Analog audio out and in
Usb
Ethernet
HPNA

The things that made me want to replace it are

1) can't build a playlist on the fly
2) the unit rips cd's poorly and I would rather not have to do it on the computer. (yes files can be transfered back and forth between the DEC and a PC)