there is a new hardware platform which, in my opinion would be an ideal choice for an open-source (hard- and software) minimyth box. Please check out http://www.omappedia.org/wiki/PandaBoard and the following images:
What is so exciting about it is that the hardware design is completely open-source. So, there are no company interests involved and the board can be sourced all around the planet. The board does not have a HDD interface, but comes with DVI-D, HDMI, composite video, USB ports, 10/100 Ethernet, Wireless, Bluetooth, 1 GB of RAM - and an TI OMAP4 processor that (theoretically) can play 1080p H.264 videos.
Given the specs, I believe that we should port MiniMyth to this board. A basic Linux implementation exists already (http://www.omappedia.org/wiki/OMAP_Ubuntu_Main), but some driver stuff (including video acceleration) still needs to be done. They have an Early Adopters Program (http://www.omappedia.org/wiki/PEAP_Projects) and I have launched a project description there. Now, it would be great to get some additional support from the community, which is why I launched this thread. Anyone willing to help is invited and encouraged to provide some positive feedback here. Given a significant support, I would post a link to this thread on the PandaBoard site and promote the project.