Was just thinking of how there is so much potential for a device made right. At a high level I would expect the following features.

1. Audio Video internet radio output Support.
2. Gigabit Network, Wireless n support.
3. Ability to stream from NAS, shared folders, Upnp devices, Shared folders, USB devices etc.
4. On Device Display for songs playing (such as Roku, squeezebox). Useful when not using monitor for controls.
5. Ability to view Control program on Monitor/TV (apple TV)
6. Optional LCD remote to allow manipulation of playlists remotely. (Sonos type)
7. Upscaling DVD Player.
8. Easy Web based Configuration.
9. Support for all major codecs and file formats.

Is there a device today which satisfies all of the above ?

Also what features would you want to add / remove to the above

I am affraid not, but if you build your own HTPC, and wait for XBMC port to linux it might :)